Починить межсерверную репликацию личных сообщений

Репликация личных сообщений между серверами теперь работает корректно.
2026-08-25 19:31:38 +04:00
parent 7d929e626e
commit 3a5851939e
21 changed files with 267 additions and 513 deletions
@@ -75,6 +75,35 @@ public final class UserAccessServersCurrentDAO {
        return result;
    }

+    /**
+     * Возвращает уникальные физические серверы из текущей routing-проекции.
+     * Используется транспортным пулом: одно WSS-соединение держится на сервер,
+     * а не на каждого пользователя этого сервера.
+     */
+    public List<UserAccessServerRouteEntry> listDistinctServers() throws SQLException {
+        String sql = """
+            SELECT DISTINCT ON (LOWER(server_login))
+                   server_login, server_url
+            FROM user_access_servers_current
+            WHERE server_login IS NOT NULL AND BTRIM(server_login) <> ''
+              AND server_url IS NOT NULL AND BTRIM(server_url) <> ''
+            ORDER BY LOWER(server_login), server_login, server_url
+            """;
+        List<UserAccessServerRouteEntry> result = new ArrayList<>();
+        try (Connection c = db.getConnection();
+             PreparedStatement ps = c.prepareStatement(sql);
+             ResultSet rs = ps.executeQuery()) {
+            while (rs.next()) {
+                UserAccessServerRouteEntry entry = new UserAccessServerRouteEntry();
+                entry.setUserLogin("");
+                entry.setServerLogin(rs.getString("server_login"));
+                entry.setServerUrl(rs.getString("server_url"));
+                result.add(entry);
+            }
+        }
+        return result;
+    }
+
    private UserAccessServerRouteEntry mapRow(ResultSet rs) throws SQLException {
        UserAccessServerRouteEntry entry = new UserAccessServerRouteEntry();
        entry.setUserLogin(rs.getString("user_login"));
@@ -4,6 +4,8 @@ import org.eclipse.jetty.websocket.api.Session;
 import shine.db.entities.CurrentUserEntry;
 import shine.db.entities.ActiveSessionEntry;

+import java.util.List;
+
 /**
 * ConnectionContext — контекст состояния одного WebSocket-соединения.
 * Живёт ровно столько же, сколько живёт подключение.
@@ -77,6 +79,12 @@ public class ConnectionContext {
     */
    private Session wsSession;

+    /** Временная server-to-server роль, заявленная через ServerHello. */
+    private boolean serverConnection;
+    private String remoteServerLogin;
+    private int remoteServerProtocolVersion;
+    private List<String> remoteServerCapabilities = List.of();
+
    // --- WebSocket Session ---

    public Session getWsSession() {
@@ -87,6 +95,20 @@ public class ConnectionContext {
        this.wsSession = wsSession;
    }

+    public boolean isServerConnection() { return serverConnection; }
+    public void setServerConnection(boolean serverConnection) { this.serverConnection = serverConnection; }
+
+    public String getRemoteServerLogin() { return remoteServerLogin; }
+    public void setRemoteServerLogin(String remoteServerLogin) { this.remoteServerLogin = remoteServerLogin; }
+
+    public int getRemoteServerProtocolVersion() { return remoteServerProtocolVersion; }
+    public void setRemoteServerProtocolVersion(int value) { this.remoteServerProtocolVersion = value; }
+
+    public List<String> getRemoteServerCapabilities() { return remoteServerCapabilities; }
+    public void setRemoteServerCapabilities(List<String> capabilities) {
+        this.remoteServerCapabilities = capabilities == null ? List.of() : List.copyOf(capabilities);
+    }
+
    // --- SolanaUser / ActiveSession ---

    public CurrentUserEntry getCurrentUser() {
@@ -188,6 +210,10 @@ public class ConnectionContext {

        authenticationStatus = AUTH_STATUS_NONE;
        wsSession = null;
+        serverConnection = false;
+        remoteServerLogin = null;
+        remoteServerProtocolVersion = 0;
+        remoteServerCapabilities = List.of();
    }

    @Override
@@ -133,6 +133,7 @@ import server.logic.ws_protocol.JSON.handlers.system.Net_ClientDebugLog_Handler;
 import server.logic.ws_protocol.JSON.handlers.system.Net_ListBlockchainHeads_Handler;
 import server.logic.ws_protocol.JSON.handlers.system.Net_CallDeliveryReport_Handler;
 import server.logic.ws_protocol.JSON.handlers.system.Net_Ping_Handler;
+import server.logic.ws_protocol.JSON.handlers.system.Net_ServerHello_Handler;
 import server.logic.ws_protocol.JSON.handlers.system.entyties.Net_CallDeliveryReport_Request;
 import server.logic.ws_protocol.JSON.handlers.system.entyties.Net_ClientErrorLog_Request;
 import server.logic.ws_protocol.JSON.handlers.system.entyties.Net_ClientDebugLog_Request;
@@ -141,6 +142,7 @@ import server.logic.ws_protocol.JSON.handlers.system.entyties.Net_GetServerInfo_
 import server.logic.ws_protocol.JSON.handlers.system.entyties.Net_GetSyncUserProfile_Request;
 import server.logic.ws_protocol.JSON.handlers.system.entyties.Net_ListBlockchainHeads_Request;
 import server.logic.ws_protocol.JSON.handlers.system.entyties.Net_Ping_Request;
+import server.logic.ws_protocol.JSON.handlers.system.entyties.Net_ServerHello_Request;

 import java.util.Map;

@@ -232,6 +234,7 @@ public final class JsonHandlerRegistry {
            Map.entry("SendSignal", new Net_SendSignal_Handler()),

            // --- system ---
+            Map.entry("ServerHello",        new Net_ServerHello_Handler()),
            Map.entry("Ping",               new Net_Ping_Handler()),
            Map.entry("GetServerInfo",      new Net_GetServerInfo_Handler()),
            Map.entry("ListBlockchainHeads", new Net_ListBlockchainHeads_Handler()),
@@ -323,6 +326,7 @@ public final class JsonHandlerRegistry {
            Map.entry("SendSignal", Net_SendSignal_Request.class),

            // --- system ---
+            Map.entry("ServerHello",        Net_ServerHello_Request.class),
            Map.entry("Ping",               Net_Ping_Request.class),
            Map.entry("GetServerInfo",      Net_GetServerInfo_Request.class),
            Map.entry("ListBlockchainHeads", Net_ListBlockchainHeads_Request.class),
@@ -123,7 +123,7 @@ public class Net_UpsertUserSetting_Handler implements JsonMessageHandler {
                        if (remoteLogin.isBlank() || remoteUrl.isBlank()) continue;
                        if (!ownServerLogin.isBlank() && remoteLogin.equalsIgnoreCase(ownServerLogin)) continue;
                        try {
-                            REMOTE.upsertUserSetting(remoteUrl, entry, true);
+                            REMOTE.upsertUserSetting(remoteLogin, remoteUrl, entry, true);
                            delivered++;
                        } catch (Exception e) {
                            log.warn("user_settings immediate sync failed: login={} remoteServer={} reason={}", login, remoteLogin, String.valueOf(e));
@@ -11,27 +11,19 @@ import shine.db.entities.BlockEntry;
 import shine.db.entities.SyncServerEntry;
 import utils.blockchain.BlockchainNameUtil;

-import java.net.URI;
-import java.net.http.HttpClient;
-import java.net.http.WebSocket;
-import java.nio.ByteBuffer;
-import java.time.Duration;
 import java.util.List;
 import java.util.Locale;
-import java.util.UUID;
 import java.util.concurrent.*;
 import java.util.concurrent.atomic.AtomicLong;

 /**
- * Фоновая one-shot репликация AddBlock на серверы из локальной таблицы sync_servers.
+ * Фоновая репликация AddBlock через общий постоянный WSS-пул на серверы
+ * из локальной таблицы sync_servers.
 */
 public final class AddBlockSyncService {

    private static final Logger log = LoggerFactory.getLogger(AddBlockSyncService.class);
    private static final ObjectMapper MAPPER = new ObjectMapper();
-    private static final HttpClient HTTP = HttpClient.newBuilder()
-            .connectTimeout(Duration.ofSeconds(6))
-            .build();
    private static final ExecutorService EXECUTOR = new ThreadPoolExecutor(
            1,
            Math.max(2, Runtime.getRuntime().availableProcessors()),
@@ -100,14 +92,14 @@ public final class AddBlockSyncService {
    }

    private void replicateToPartner(SyncServerEntry partner, String blockchainName, int blockNumber, BlockEntry currentBlock) throws Exception {
-        String wsUrl = buildWsUrl(partner.getServerAddress());
+        String wsUrl = ServerConnectionPool.buildWsUrl(partner.getServerAddress());
        if (wsUrl == null) {
            log.warn("AddBlock sync skipped: invalid server_address for partner login={} address={}",
                    partner.getLogin(), partner.getServerAddress());
            return;
        }

-        AddBlockPushResult firstTry = pushBlock(wsUrl, blockchainName, currentBlock);
+        AddBlockPushResult firstTry = pushBlock(partner, blockchainName, currentBlock);
        if (firstTry.ok()) {
            log.info("AddBlock sync ok: partner={} blockchainName={} blockNumber={}",
                    partner.getLogin(), blockchainName, blockNumber);
@@ -142,7 +134,7 @@ public final class AddBlockSyncService {
        }

        for (BlockEntry blockEntry : missingBlocks) {
-            AddBlockPushResult backfillResult = pushBlock(wsUrl, blockchainName, blockEntry);
+            AddBlockPushResult backfillResult = pushBlock(partner, blockchainName, blockEntry);
            if (!backfillResult.ok()) {
                log.warn("AddBlock sync backfill failed: partner={} blockchainName={} blockNumber={} code={}",
                        partner.getLogin(), blockchainName, blockEntry.getBlockNumber(), backfillResult.code());
@@ -154,8 +146,8 @@ public final class AddBlockSyncService {
                partner.getLogin(), blockchainName, fromBlockNumber, blockNumber);
    }

-    private AddBlockPushResult pushBlock(String wsUrl, String blockchainName, BlockEntry blockEntry) throws Exception {
-        JsonNode response = sendAddBlock(wsUrl, blockchainName, blockEntry);
+    private AddBlockPushResult pushBlock(SyncServerEntry partner, String blockchainName, BlockEntry blockEntry) throws Exception {
+        JsonNode response = sendAddBlock(partner, blockchainName, blockEntry);
        int status = response.path("status").asInt(500);
        if (status >= 200 && status < 300) {
            return AddBlockPushResult.success();
@@ -172,31 +164,16 @@ public final class AddBlockSyncService {
        return new AddBlockPushResult(false, status, code, serverLastGlobalNumber, serverLastGlobalHash);
    }

-    private JsonNode sendAddBlock(String wsUrl, String blockchainName, BlockEntry blockEntry) throws Exception {
-        CompletableFuture<String> responseFuture = new CompletableFuture<>();
-        CountDownLatch openLatch = new CountDownLatch(1);
-        SyncWsListener listener = new SyncWsListener(responseFuture, openLatch);
-
-        WebSocket webSocket = HTTP.newWebSocketBuilder()
-                .connectTimeout(Duration.ofSeconds(6))
-                .buildAsync(URI.create(wsUrl), listener)
-                .get(8, TimeUnit.SECONDS);
-
-        if (!openLatch.await(8, TimeUnit.SECONDS)) {
-            tryAbort(webSocket);
-            throw new TimeoutException("WS open timeout");
-        }
-
-        String requestId = "sync-" + UUID.randomUUID();
-        String json = buildAddBlockJson(requestId, blockchainName, blockEntry);
-        webSocket.sendText(json, true).get(8, TimeUnit.SECONDS);
-
-        String responseJson = responseFuture.get(12, TimeUnit.SECONDS);
-        tryAbort(webSocket);
-        return MAPPER.readTree(responseJson);
+    private JsonNode sendAddBlock(SyncServerEntry partner, String blockchainName, BlockEntry blockEntry) throws Exception {
+        String jsonTemplate = buildAddBlockJsonTemplate(blockchainName, blockEntry);
+        return ServerConnectionPool.getInstance().request(
+                partner.getLogin(),
+                partner.getServerAddress(),
+                jsonTemplate,
+                ServerConnectionPool.Priority.BULK);
    }

-    private String buildAddBlockJson(String requestId, String blockchainName, BlockEntry blockEntry) throws Exception {
+    private String buildAddBlockJsonTemplate(String blockchainName, BlockEntry blockEntry) throws Exception {
        String prevHashHex = blockEntry.getBlockNumber() <= 0
                ? ""
                : toHex(extractPrevHash32(blockEntry.getBlockBytes()));
@@ -205,8 +182,6 @@ public final class AddBlockSyncService {
        String safeBlockchainName = MAPPER.writeValueAsString(blockchainName);
        String safePrevHashHex = MAPPER.writeValueAsString(prevHashHex);
        String safeBlockBytes = MAPPER.writeValueAsString(blockBytesB64);
-        String safeRequestId = MAPPER.writeValueAsString(requestId);
-
        return """
            {
              "op":"AddBlock",
@@ -218,7 +193,7 @@ public final class AddBlockSyncService {
                "blockBytesB64":%s
              }
            }
-            """.formatted(safeRequestId, safeBlockchainName, blockEntry.getBlockNumber(), safePrevHashHex, safeBlockBytes);
+            """.formatted("%s", safeBlockchainName, blockEntry.getBlockNumber(), safePrevHashHex, safeBlockBytes);
    }

    private static byte[] extractPrevHash32(byte[] blockBytes) {
@@ -240,32 +215,6 @@ public final class AddBlockSyncService {
        return s.isEmpty() ? null : s;
    }

-    private static String buildWsUrl(String serverAddressRaw) {
-        String host = normalizeHostLike(serverAddressRaw);
-        if (host == null) return null;
-        return "wss://" + host + "/ws";
-    }
-
-    private static String normalizeHostLike(String value) {
-        if (value == null) return null;
-        String raw = value.trim();
-        if (raw.isEmpty()) return null;
-        try {
-            String withScheme = raw.matches("^[a-zA-Z]+://.*$") ? raw : "https://" + raw;
-            URI uri = URI.create(withScheme);
-            String host = uri.getHost();
-            if (host == null || host.isBlank()) return null;
-            return host.trim().toLowerCase(Locale.ROOT);
-        } catch (Exception e) {
-            String cleaned = raw
-                    .replaceFirst("^[a-zA-Z]+://", "")
-                    .replaceFirst("/.*$", "")
-                    .trim()
-                    .toLowerCase(Locale.ROOT);
-            return cleaned.isEmpty() ? null : cleaned;
-        }
-    }
-
    private static String toHex(byte[] bytes) {
        if (bytes == null) return "";
        StringBuilder sb = new StringBuilder(bytes.length * 2);
@@ -276,17 +225,6 @@ public final class AddBlockSyncService {
        return sb.toString();
    }

-    private static void tryAbort(WebSocket webSocket) {
-        try {
-            webSocket.sendClose(WebSocket.NORMAL_CLOSURE, "ok");
-        } catch (Exception ignored) {
-        }
-        try {
-            webSocket.abort();
-        } catch (Exception ignored) {
-        }
-    }
-
    private record AddBlockPushResult(
            boolean ok,
            int status,
@@ -309,52 +247,4 @@ public final class AddBlockSyncService {
        }
    }

-    private static final class SyncWsListener implements WebSocket.Listener {
-        private final CompletableFuture<String> responseFuture;
-        private final CountDownLatch openLatch;
-        private final StringBuilder textBuffer = new StringBuilder();
-
-        private SyncWsListener(CompletableFuture<String> responseFuture, CountDownLatch openLatch) {
-            this.responseFuture = responseFuture;
-            this.openLatch = openLatch;
-        }
-
-        @Override
-        public void onOpen(WebSocket webSocket) {
-            openLatch.countDown();
-            webSocket.request(1);
-        }
-
-        @Override
-        public CompletionStage<?> onText(WebSocket webSocket, CharSequence data, boolean last) {
-            textBuffer.append(data);
-            if (last && !responseFuture.isDone()) {
-                responseFuture.complete(textBuffer.toString());
-            }
-            webSocket.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public CompletionStage<?> onBinary(WebSocket webSocket, ByteBuffer data, boolean last) {
-            webSocket.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public CompletionStage<?> onClose(WebSocket webSocket, int statusCode, String reason) {
-            if (!responseFuture.isDone()) {
-                responseFuture.completeExceptionally(new IllegalStateException("WS closed before response: " + statusCode + " " + reason));
-            }
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public void onError(WebSocket webSocket, Throwable error) {
-            if (!responseFuture.isDone()) {
-                responseFuture.completeExceptionally(error);
-            }
-            openLatch.countDown();
-        }
-    }
 }
@@ -149,7 +149,8 @@ public final class DmDeliveryCoordinator {
            completion.submit(() -> {
                try {
                    if (!routeLogin.equals(ownServerLogin)) {
-                        REMOTE.receiveIncomingMessage(route.getServerUrl(), incomingBlobB64, ownServerLogin);
+                        REMOTE.receiveIncomingMessage(
+                                routeLogin, route.getServerUrl(), incomingBlobB64, ownServerLogin);
                    }
                    return new RouteAttempt(routeLogin, null);
                } catch (Exception e) {
@@ -188,6 +189,7 @@ public final class DmDeliveryCoordinator {
        if (incoming == null || outgoing == null) return current;
        try {
            REMOTE.sendMessagePair(
+                    peer.getServerLogin(),
                    peer.getServerUrl(),
                    Base64.getEncoder().encodeToString(incoming.getRawBlock()),
                    Base64.getEncoder().encodeToString(outgoing.getRawBlock()),
@@ -204,7 +206,7 @@ public final class DmDeliveryCoordinator {
        if (peer == null) return current;
        try {
            RemoteDmSyncClient.RemoteDeliveryStatus remote = REMOTE.getDmDeliveryStatus(
-                    peer.getServerUrl(), current.getOutgoingMessageKey());
+                    peer.getServerLogin(), peer.getServerUrl(), current.getOutgoingMessageKey());
            if (remote.known() && remote.delivered()) {
                return DELIVERY_DAO.markDeliveredFromPeer(current.getEventId(), System.currentTimeMillis());
            }
@@ -27,12 +27,15 @@ public final class DmFederationService {
            String ownServerLogin = ownServerLogin();
            for (UserAccessServerRouteEntry route : senderRoutes.values()) {
                if (isOwnServer(route, ownServerLogin)) continue;
-                REMOTE.sendMessagePair(route.getServerUrl(), incomingBlobB64, outgoingBlobB64, ownServerLogin);
+                REMOTE.sendMessagePair(
+                        route.getServerLogin(), route.getServerUrl(),
+                        incomingBlobB64, outgoingBlobB64, ownServerLogin);
            }
            for (UserAccessServerRouteEntry route : recipientRoutes.values()) {
                if (isOwnServer(route, ownServerLogin)) continue;
                if (senderRoutes.containsKey(normalize(route.getServerLogin()))) continue;
-                REMOTE.receiveIncomingMessage(route.getServerUrl(), incomingBlobB64, ownServerLogin);
+                REMOTE.receiveIncomingMessage(
+                        route.getServerLogin(), route.getServerUrl(), incomingBlobB64, ownServerLogin);
            }
        } catch (Exception e) {
            log.warn("DM federation pair fan-out failed: from={} to={}", fromLogin, toLogin, e);
@@ -54,7 +57,8 @@ public final class DmFederationService {
                if (routeLogin == null) continue;
                if (ownServerLogin != null && ownServerLogin.equalsIgnoreCase(routeLogin)) continue;
                if (normalizedSource != null && normalizedSource.equalsIgnoreCase(routeLogin)) continue;
-                REMOTE.receiveIncomingMessage(route.getServerUrl(), incomingBlobB64, ownServerLogin);
+                REMOTE.receiveIncomingMessage(
+                        route.getServerLogin(), route.getServerUrl(), incomingBlobB64, ownServerLogin);
            }
        } catch (Exception e) {
            log.warn("DM federation incoming relay failed: to={}", toLogin, e);
@@ -79,9 +83,9 @@ public final class DmFederationService {
            for (UserAccessServerRouteEntry route : routes.values()) {
                if (isOwnServer(route, ownServerLogin)) continue;
                if (oneMessageDelete) {
-                    REMOTE.deleteMessage(route.getServerUrl(), blobB64);
+                    REMOTE.deleteMessage(route.getServerLogin(), route.getServerUrl(), blobB64);
                } else {
-                    REMOTE.deleteConversation(route.getServerUrl(), blobB64);
+                    REMOTE.deleteConversation(route.getServerLogin(), route.getServerUrl(), blobB64);
                }
            }
        } catch (Exception e) {
@@ -2,37 +2,22 @@ package server.sync;

 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.net.URI;
-import java.net.http.HttpClient;
-import java.net.http.WebSocket;
-import java.nio.ByteBuffer;
-import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Locale;
-import java.util.UUID;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.CompletionStage;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;

 /**
 * Минимальный клиент для межсерверных JSON-op запросов по WSS.
 */
 public final class RemoteBlockchainSyncClient {

-    private static final Logger log = LoggerFactory.getLogger(RemoteBlockchainSyncClient.class);
    private static final ObjectMapper MAPPER = new ObjectMapper();
-    private static final HttpClient HTTP = HttpClient.newBuilder()
-            .connectTimeout(Duration.ofSeconds(6))
-            .build();

    public List<RemoteBlockchainHead> listBlockchainHeads(String serverAddressRaw) throws Exception {
-        JsonNode response = send(serverAddressRaw, """
+        return listBlockchainHeads(null, serverAddressRaw);
+    }
+
+    public List<RemoteBlockchainHead> listBlockchainHeads(String serverLogin, String serverAddressRaw) throws Exception {
+        JsonNode response = send(serverLogin, serverAddressRaw, """
            {
              "op":"ListBlockchainHeads",
              "requestId":%s,
@@ -62,8 +47,12 @@ public final class RemoteBlockchainSyncClient {
    }

    public RemoteSyncUserProfile getSyncUserProfile(String serverAddressRaw, String login) throws Exception {
+        return getSyncUserProfile(null, serverAddressRaw, login);
+    }
+
+    public RemoteSyncUserProfile getSyncUserProfile(String serverLogin, String serverAddressRaw, String login) throws Exception {
        String safeLogin = MAPPER.writeValueAsString(login);
-        JsonNode response = send(serverAddressRaw, """
+        JsonNode response = send(serverLogin, serverAddressRaw, """
            {
              "op":"GetSyncUserProfile",
              "requestId":%s,
@@ -96,9 +85,17 @@ public final class RemoteBlockchainSyncClient {
        );
    }

-    public RemoteBlockchainBlock getBlockchainBlock(String serverAddressRaw, String blockchainName, int blockNumber) throws Exception {
+    public RemoteBlockchainBlock getBlockchainBlock(
+            String serverAddressRaw, String blockchainName, int blockNumber
+    ) throws Exception {
+        return getBlockchainBlock(null, serverAddressRaw, blockchainName, blockNumber);
+    }
+
+    public RemoteBlockchainBlock getBlockchainBlock(
+            String serverLogin, String serverAddressRaw, String blockchainName, int blockNumber
+    ) throws Exception {
        String safeBlockchainName = MAPPER.writeValueAsString(blockchainName);
-        JsonNode response = send(serverAddressRaw, """
+        JsonNode response = send(serverLogin, serverAddressRaw, """
            {
              "op":"GetBlockchainBlock",
              "requestId":%s,
@@ -126,32 +123,12 @@ public final class RemoteBlockchainSyncClient {
        );
    }

-    private JsonNode send(String serverAddressRaw, String jsonTemplate) throws Exception {
-        String requestId = MAPPER.writeValueAsString("sync-" + UUID.randomUUID());
-        String json = jsonTemplate.formatted(requestId);
-        String wsUrl = buildWsUrl(serverAddressRaw);
-        if (wsUrl == null) {
-            throw new IllegalArgumentException("Invalid server address: " + serverAddressRaw);
-        }
-
-        CompletableFuture<String> responseFuture = new CompletableFuture<>();
-        CountDownLatch openLatch = new CountDownLatch(1);
-        SyncWsListener listener = new SyncWsListener(responseFuture, openLatch);
-
-        WebSocket webSocket = HTTP.newWebSocketBuilder()
-                .connectTimeout(Duration.ofSeconds(6))
-                .buildAsync(URI.create(wsUrl), listener)
-                .get(8, TimeUnit.SECONDS);
-
-        if (!openLatch.await(8, TimeUnit.SECONDS)) {
-            tryAbort(webSocket);
-            throw new TimeoutException("WS open timeout");
-        }
-
-        webSocket.sendText(json, true).get(8, TimeUnit.SECONDS);
-        String responseJson = responseFuture.get(12, TimeUnit.SECONDS);
-        tryAbort(webSocket);
-        return MAPPER.readTree(responseJson);
+    private JsonNode send(String serverLogin, String serverAddressRaw, String jsonTemplate) throws Exception {
+        return ServerConnectionPool.getInstance().request(
+                serverLogin,
+                serverAddressRaw,
+                jsonTemplate,
+                ServerConnectionPool.Priority.BULK);
    }

    private static String errorCode(JsonNode response) {
@@ -161,40 +138,7 @@ public final class RemoteBlockchainSyncClient {
    }

    static String buildWsUrl(String serverAddressRaw) {
-        String host = normalizeHostLike(serverAddressRaw);
-        if (host == null) return null;
-        return "wss://" + host + "/ws";
-    }
-
-    private static String normalizeHostLike(String value) {
-        if (value == null) return null;
-        String raw = value.trim();
-        if (raw.isEmpty()) return null;
-        try {
-            String withScheme = raw.matches("^[a-zA-Z]+://.*$") ? raw : "https://" + raw;
-            URI uri = URI.create(withScheme);
-            String host = uri.getHost();
-            if (host == null || host.isBlank()) return null;
-            return host.trim().toLowerCase(Locale.ROOT);
-        } catch (Exception e) {
-            String cleaned = raw
-                    .replaceFirst("^[a-zA-Z]+://", "")
-                    .replaceFirst("/.*$", "")
-                    .trim()
-                    .toLowerCase(Locale.ROOT);
-            return cleaned.isEmpty() ? null : cleaned;
-        }
-    }
-
-    private static void tryAbort(WebSocket webSocket) {
-        try {
-            webSocket.sendClose(WebSocket.NORMAL_CLOSURE, "ok");
-        } catch (Exception ignored) {
-        }
-        try {
-            webSocket.abort();
-        } catch (Exception ignored) {
-        }
+        return ServerConnectionPool.buildWsUrl(serverAddressRaw);
    }

    public record RemoteBlockchainHead(
@@ -220,53 +164,4 @@ public final class RemoteBlockchainSyncClient {
            long blockchainSizeLimitBytes
    ) {}

-    private static final class SyncWsListener implements WebSocket.Listener {
-        private final CompletableFuture<String> responseFuture;
-        private final CountDownLatch openLatch;
-        private final StringBuilder textBuffer = new StringBuilder();
-
-        private SyncWsListener(CompletableFuture<String> responseFuture, CountDownLatch openLatch) {
-            this.responseFuture = responseFuture;
-            this.openLatch = openLatch;
-        }
-
-        @Override
-        public void onOpen(WebSocket webSocket) {
-            openLatch.countDown();
-            webSocket.request(1);
-        }
-
-        @Override
-        public CompletionStage<?> onText(WebSocket webSocket, CharSequence data, boolean last) {
-            textBuffer.append(data);
-            if (last && !responseFuture.isDone()) {
-                responseFuture.complete(textBuffer.toString());
-            }
-            webSocket.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public CompletionStage<?> onBinary(WebSocket webSocket, ByteBuffer data, boolean last) {
-            webSocket.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public CompletionStage<?> onClose(WebSocket webSocket, int statusCode, String reason) {
-            if (!responseFuture.isDone()) {
-                responseFuture.completeExceptionally(new IllegalStateException("WS closed before response: " + statusCode + " " + reason));
-            }
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public void onError(WebSocket webSocket, Throwable error) {
-            log.warn("Remote sync websocket error: {}", String.valueOf(error));
-            if (!responseFuture.isDone()) {
-                responseFuture.completeExceptionally(error);
-            }
-            openLatch.countDown();
-        }
-    }
 }
@@ -3,37 +3,33 @@ package server.sync;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;

-import java.net.URI;
-import java.net.http.HttpClient;
-import java.net.http.WebSocket;
-import java.nio.ByteBuffer;
-import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.UUID;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.CompletionStage;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;

 /** Клиент стабильных межсерверных DM-операций. */
 public final class RemoteDmSyncClient {
    private static final ObjectMapper MAPPER = new ObjectMapper();
-    private static final HttpClient HTTP = HttpClient.newBuilder()
-            .connectTimeout(Duration.ofSeconds(6))
-            .build();

    public void sendMessagePair(
            String serverAddressRaw,
            String incomingBlobB64,
            String outgoingBlobB64,
            String sourceServerLogin
+    ) throws Exception {
+        sendMessagePair(null, serverAddressRaw, incomingBlobB64, outgoingBlobB64, sourceServerLogin);
+    }
+
+    public void sendMessagePair(
+            String targetServerLogin,
+            String serverAddressRaw,
+            String incomingBlobB64,
+            String outgoingBlobB64,
+            String sourceServerLogin
    ) throws Exception {
        String incomingJson = MAPPER.writeValueAsString(incomingBlobB64);
        String outgoingJson = MAPPER.writeValueAsString(outgoingBlobB64);
        String sourceServerLoginJson = toOptionalJsonField("sourceServerLogin", sourceServerLogin);
-        JsonNode response = send(serverAddressRaw, """
+        JsonNode response = send(targetServerLogin, serverAddressRaw, """
            {
              "op":"ReceiveOutcomingMessage",
              "requestId":%s,
@@ -50,10 +46,19 @@ public final class RemoteDmSyncClient {
            String serverAddressRaw,
            String incomingBlobB64,
            String sourceServerLogin
+    ) throws Exception {
+        receiveIncomingMessage(null, serverAddressRaw, incomingBlobB64, sourceServerLogin);
+    }
+
+    public void receiveIncomingMessage(
+            String targetServerLogin,
+            String serverAddressRaw,
+            String incomingBlobB64,
+            String sourceServerLogin
    ) throws Exception {
        String incomingJson = MAPPER.writeValueAsString(incomingBlobB64);
        String sourceServerLoginJson = toOptionalJsonField("sourceServerLogin", sourceServerLogin);
-        JsonNode response = send(serverAddressRaw, """
+        JsonNode response = send(targetServerLogin, serverAddressRaw, """
            {
              "op":"ReceiveIncomingMessage",
              "requestId":%s,
@@ -66,8 +71,14 @@ public final class RemoteDmSyncClient {
    }

    public RemoteDeliveryStatus getDmDeliveryStatus(String serverAddressRaw, String messageKey) throws Exception {
+        return getDmDeliveryStatus(null, serverAddressRaw, messageKey);
+    }
+
+    public RemoteDeliveryStatus getDmDeliveryStatus(
+            String targetServerLogin, String serverAddressRaw, String messageKey
+    ) throws Exception {
        String messageKeyJson = MAPPER.writeValueAsString(messageKey);
-        JsonNode response = send(serverAddressRaw, """
+        JsonNode response = send(targetServerLogin, serverAddressRaw, """
            {
              "op":"GetDmDeliveryStatus",
              "requestId":%s,
@@ -94,7 +105,21 @@ public final class RemoteDmSyncClient {
            int maxBytes,
            List<String> ackSyncIds
    ) throws Exception {
-        try (RemoteSyncSession session = new RemoteSyncSession(serverAddressRaw)) {
+        return dmSyncBatch(null, serverAddressRaw, ownerLogin, afterStoredAtMs,
+                afterMessageKey, limit, maxBytes, ackSyncIds);
+    }
+
+    public RemoteDmBatch dmSyncBatch(
+            String targetServerLogin,
+            String serverAddressRaw,
+            String ownerLogin,
+            long afterStoredAtMs,
+            String afterMessageKey,
+            int limit,
+            int maxBytes,
+            List<String> ackSyncIds
+    ) throws Exception {
+        try (RemoteSyncSession session = new RemoteSyncSession(targetServerLogin, serverAddressRaw)) {
            return dmSyncBatch(session, ownerLogin, afterStoredAtMs, afterMessageKey,
                    limit, maxBytes, ackSyncIds);
        }
@@ -156,8 +181,12 @@ public final class RemoteDmSyncClient {
    }

    public void deleteMessage(String serverAddressRaw, String blobB64) throws Exception {
+        deleteMessage(null, serverAddressRaw, blobB64);
+    }
+
+    public void deleteMessage(String targetServerLogin, String serverAddressRaw, String blobB64) throws Exception {
        String blobJson = MAPPER.writeValueAsString(blobB64);
-        JsonNode response = send(serverAddressRaw, """
+        JsonNode response = send(targetServerLogin, serverAddressRaw, """
            {
              "op":"DeleteMessage",
              "requestId":%s,
@@ -168,8 +197,12 @@ public final class RemoteDmSyncClient {
    }

    public void deleteConversation(String serverAddressRaw, String blobB64) throws Exception {
+        deleteConversation(null, serverAddressRaw, blobB64);
+    }
+
+    public void deleteConversation(String targetServerLogin, String serverAddressRaw, String blobB64) throws Exception {
        String blobJson = MAPPER.writeValueAsString(blobB64);
-        JsonNode response = send(serverAddressRaw, """
+        JsonNode response = send(targetServerLogin, serverAddressRaw, """
            {
              "op":"DeleteConversation",
              "requestId":%s,
@@ -179,27 +212,12 @@ public final class RemoteDmSyncClient {
        ensureOk("DeleteConversation", response);
    }

-    private JsonNode send(String serverAddressRaw, String jsonTemplate) throws Exception {
-        String requestId = MAPPER.writeValueAsString("dm-sync-" + UUID.randomUUID());
-        String json = jsonTemplate.formatted(requestId);
-        String wsUrl = RemoteBlockchainSyncClient.buildWsUrl(serverAddressRaw);
-        if (wsUrl == null) throw new IllegalArgumentException("Invalid server address: " + serverAddressRaw);
-
-        CompletableFuture<String> responseFuture = new CompletableFuture<>();
-        CountDownLatch openLatch = new CountDownLatch(1);
-        SyncWsListener listener = new SyncWsListener(responseFuture, openLatch);
-        WebSocket webSocket = HTTP.newWebSocketBuilder()
-                .connectTimeout(Duration.ofSeconds(6))
-                .buildAsync(URI.create(wsUrl), listener)
-                .get(8, TimeUnit.SECONDS);
-        if (!openLatch.await(8, TimeUnit.SECONDS)) {
-            tryAbort(webSocket);
-            throw new TimeoutException("WS open timeout");
-        }
-        webSocket.sendText(json, true).get(8, TimeUnit.SECONDS);
-        String responseJson = responseFuture.get(12, TimeUnit.SECONDS);
-        tryAbort(webSocket);
-        return MAPPER.readTree(responseJson);
+    private JsonNode send(String targetServerLogin, String serverAddressRaw, String jsonTemplate) throws Exception {
+        return ServerConnectionPool.getInstance().request(
+                targetServerLogin,
+                serverAddressRaw,
+                jsonTemplate,
+                ServerConnectionPool.Priority.REALTIME);
    }

    private String toOptionalJsonField(String fieldName, String value) throws Exception {
@@ -215,60 +233,10 @@ public final class RemoteDmSyncClient {
        throw new IllegalStateException(op + " failed: status=" + status + " code=" + code);
    }

-    private static void tryAbort(WebSocket webSocket) {
-        try { webSocket.sendClose(WebSocket.NORMAL_CLOSURE, "ok"); } catch (Exception ignored) {}
-        try { webSocket.abort(); } catch (Exception ignored) {}
-    }
-
    public record RemoteDeliveryStatus(String messageKey, boolean known, boolean delivered) {}
    public record RemoteDmBatch(long nextStoredAtMs, String nextMessageKey, boolean hasMore, List<RemoteDmItem> items) {}
    public record RemoteDmItem(
            String syncId, String primaryMessageKey, long storedAtMs, List<String> blobsB64
    ) {}

-    private static final class SyncWsListener implements WebSocket.Listener {
-        private final CompletableFuture<String> responseFuture;
-        private final CountDownLatch openLatch;
-        private final StringBuilder textBuffer = new StringBuilder();
-
-        private SyncWsListener(CompletableFuture<String> responseFuture, CountDownLatch openLatch) {
-            this.responseFuture = responseFuture;
-            this.openLatch = openLatch;
-        }
-
-        @Override
-        public void onOpen(WebSocket webSocket) {
-            openLatch.countDown();
-            webSocket.request(1);
-        }
-
-        @Override
-        public CompletionStage<?> onText(WebSocket webSocket, CharSequence data, boolean last) {
-            textBuffer.append(data);
-            if (last && !responseFuture.isDone()) responseFuture.complete(textBuffer.toString());
-            webSocket.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public CompletionStage<?> onBinary(WebSocket webSocket, ByteBuffer data, boolean last) {
-            webSocket.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public CompletionStage<?> onClose(WebSocket webSocket, int statusCode, String reason) {
-            if (!responseFuture.isDone()) {
-                responseFuture.completeExceptionally(
-                        new IllegalStateException("WS closed before response: " + statusCode + " " + reason));
-            }
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public void onError(WebSocket webSocket, Throwable error) {
-            if (!responseFuture.isDone()) responseFuture.completeExceptionally(error);
-            openLatch.countDown();
-        }
-    }
 }
@@ -1,70 +1,35 @@
 package server.sync;

 import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectMapper;

-import java.net.URI;
-import java.net.http.HttpClient;
-import java.net.http.WebSocket;
-import java.nio.ByteBuffer;
-import java.time.Duration;
-import java.util.UUID;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.CompletionStage;
-import java.util.concurrent.LinkedBlockingQueue;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;
-
-/** Один последовательный WS-сеанс для синхронизации всех данных access-сервера. */
+/**
+ * Логический последовательный сеанс поверх общего постоянного WSS-пула.
+ * close() больше не закрывает физическое соединение с сервером.
+ */
 public final class RemoteSyncSession implements AutoCloseable {
-    private static final ObjectMapper MAPPER = new ObjectMapper();
-    private static final HttpClient HTTP = HttpClient.newBuilder()
-            .connectTimeout(Duration.ofSeconds(6)).build();
-    private final LinkedBlockingQueue<String> responses = new LinkedBlockingQueue<>();
-    private final WebSocket webSocket;
+    private final String serverLogin;
+    private final String serverAddress;

+    /** Совместимый конструктор: при отсутствии логина пул использует адрес как ключ peer. */
    public RemoteSyncSession(String serverAddressRaw) throws Exception {
-        String wsUrl = RemoteBlockchainSyncClient.buildWsUrl(serverAddressRaw);
-        if (wsUrl == null) throw new IllegalArgumentException("Invalid server address: " + serverAddressRaw);
-        Listener listener = new Listener(responses);
-        webSocket = HTTP.newWebSocketBuilder().connectTimeout(Duration.ofSeconds(6))
-                .buildAsync(URI.create(wsUrl), listener).get(8, TimeUnit.SECONDS);
+        this(null, serverAddressRaw);
+    }
+
+    public RemoteSyncSession(String serverLogin, String serverAddressRaw) {
+        this.serverLogin = serverLogin;
+        this.serverAddress = serverAddressRaw;
    }

    public synchronized JsonNode send(String jsonTemplate) throws Exception {
-        String requestId = MAPPER.writeValueAsString("access-sync-" + UUID.randomUUID());
-        webSocket.sendText(jsonTemplate.formatted(requestId), true).get(8, TimeUnit.SECONDS);
-        String json = responses.poll(12, TimeUnit.SECONDS);
-        if (json == null) throw new TimeoutException("WS response timeout");
-        return MAPPER.readTree(json);
+        return ServerConnectionPool.getInstance().request(
+                serverLogin,
+                serverAddress,
+                jsonTemplate,
+                ServerConnectionPool.Priority.NORMAL);
    }

    @Override
    public void close() {
-        try { webSocket.sendClose(WebSocket.NORMAL_CLOSURE, "ok"); } catch (Exception ignored) {}
-    }
-
-    private static final class Listener implements WebSocket.Listener {
-        private final LinkedBlockingQueue<String> responses;
-        private final StringBuilder text = new StringBuilder();
-
-        private Listener(LinkedBlockingQueue<String> responses) { this.responses = responses; }
-        @Override public void onOpen(WebSocket ws) { ws.request(1); }
-        @Override public CompletionStage<?> onText(WebSocket ws, CharSequence data, boolean last) {
-            text.append(data);
-            if (last) {
-                responses.offer(text.toString());
-                text.setLength(0);
-            }
-            ws.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-        @Override public CompletionStage<?> onBinary(WebSocket ws, ByteBuffer data, boolean last) {
-            ws.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-        @Override public void onError(WebSocket ws, Throwable error) {
-            responses.offer("{\"status\":500,\"code\":\"WS_ERROR\"}");
-        }
+        // Физическое соединение принадлежит ServerConnectionPool.
    }
 }
@@ -4,27 +4,22 @@ import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import shine.db.entities.UserSettingEntry;

-import java.net.URI;
-import java.net.http.HttpClient;
-import java.net.http.WebSocket;
-import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.UUID;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.CompletionStage;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.TimeoutException;

 public final class RemoteUserSettingsSyncClient {
    private static final ObjectMapper MAPPER = new ObjectMapper();
-    private static final HttpClient HTTP = HttpClient.newBuilder()
-            .connectTimeout(Duration.ofSeconds(6))
-            .build();

-    public void upsertUserSetting(String serverAddressRaw, UserSettingEntry entry, boolean syncDelivery) throws Exception {
-        try (RemoteSyncSession session = new RemoteSyncSession(serverAddressRaw)) {
+    public void upsertUserSetting(
+            String serverAddressRaw, UserSettingEntry entry, boolean syncDelivery
+    ) throws Exception {
+        upsertUserSetting(null, serverAddressRaw, entry, syncDelivery);
+    }
+
+    public void upsertUserSetting(
+            String targetServerLogin, String serverAddressRaw, UserSettingEntry entry, boolean syncDelivery
+    ) throws Exception {
+        try (RemoteSyncSession session = new RemoteSyncSession(targetServerLogin, serverAddressRaw)) {
            upsertUserSetting(session, entry, syncDelivery);
        }
    }
@@ -69,7 +64,20 @@ public final class RemoteUserSettingsSyncClient {
            int limit,
            int maxBytes
    ) throws Exception {
-        try (RemoteSyncSession session = new RemoteSyncSession(serverAddressRaw)) {
+        return userSettingsSyncBatch(null, serverAddressRaw, ownerLogin,
+                afterTimeMs, afterSettingKey, limit, maxBytes);
+    }
+
+    public RemoteUserSettingsBatch userSettingsSyncBatch(
+            String targetServerLogin,
+            String serverAddressRaw,
+            String ownerLogin,
+            long afterTimeMs,
+            String afterSettingKey,
+            int limit,
+            int maxBytes
+    ) throws Exception {
+        try (RemoteSyncSession session = new RemoteSyncSession(targetServerLogin, serverAddressRaw)) {
            return userSettingsSyncBatch(session, ownerLogin, afterTimeMs, afterSettingKey, limit, maxBytes);
        }
    }
@@ -129,34 +137,6 @@ public final class RemoteUserSettingsSyncClient {
        );
    }

-    private JsonNode send(String serverAddressRaw, String jsonTemplate) throws Exception {
-        String requestId = MAPPER.writeValueAsString("user-settings-sync-" + UUID.randomUUID());
-        String json = jsonTemplate.formatted(requestId);
-        String wsUrl = RemoteBlockchainSyncClient.buildWsUrl(serverAddressRaw);
-        if (wsUrl == null) {
-            throw new IllegalArgumentException("Invalid server address: " + serverAddressRaw);
-        }
-
-        CompletableFuture<String> responseFuture = new CompletableFuture<>();
-        CountDownLatch openLatch = new CountDownLatch(1);
-        SyncWsListener listener = new SyncWsListener(responseFuture, openLatch);
-
-        WebSocket webSocket = HTTP.newWebSocketBuilder()
-                .connectTimeout(Duration.ofSeconds(6))
-                .buildAsync(URI.create(wsUrl), listener)
-                .get(8, TimeUnit.SECONDS);
-
-        if (!openLatch.await(8, TimeUnit.SECONDS)) {
-            tryAbort(webSocket);
-            throw new TimeoutException("WS open timeout");
-        }
-
-        webSocket.sendText(json, true).get(8, TimeUnit.SECONDS);
-        String responseJson = responseFuture.get(12, TimeUnit.SECONDS);
-        tryAbort(webSocket);
-        return MAPPER.readTree(responseJson);
-    }
-
    private void ensureOk(String op, JsonNode response) {
        int status = response.path("status").asInt(500);
        if (status >= 200 && status < 300) return;
@@ -165,17 +145,6 @@ public final class RemoteUserSettingsSyncClient {
        throw new IllegalStateException(op + " failed: status=" + status + " code=" + code);
    }

-    private static void tryAbort(WebSocket webSocket) {
-        try {
-            webSocket.sendClose(WebSocket.NORMAL_CLOSURE, "ok");
-        } catch (Exception ignored) {
-        }
-        try {
-            webSocket.abort();
-        } catch (Exception ignored) {
-        }
-    }
-
    public record RemoteUserSettingsBatch(
            long nextTimeMs,
            String nextSettingKey,
@@ -194,35 +163,4 @@ public final class RemoteUserSettingsSyncClient {
            String signature
    ) {}

-    private static final class SyncWsListener implements WebSocket.Listener {
-        private final CompletableFuture<String> responseFuture;
-        private final CountDownLatch openLatch;
-        private final StringBuilder textBuffer = new StringBuilder();
-
-        private SyncWsListener(CompletableFuture<String> responseFuture, CountDownLatch openLatch) {
-            this.responseFuture = responseFuture;
-            this.openLatch = openLatch;
-        }
-
-        @Override
-        public void onOpen(WebSocket webSocket) {
-            openLatch.countDown();
-            webSocket.request(1);
-        }
-
-        @Override
-        public CompletionStage<?> onText(WebSocket webSocket, CharSequence data, boolean last) {
-            textBuffer.append(data);
-            if (last && !responseFuture.isDone()) {
-                responseFuture.complete(textBuffer.toString());
-            }
-            webSocket.request(1);
-            return CompletableFuture.completedFuture(null);
-        }
-
-        @Override
-        public void onError(WebSocket webSocket, Throwable error) {
-            responseFuture.completeExceptionally(error);
-        }
-    }
 }
@@ -67,7 +67,8 @@ public final class BlockchainResyncRecoveryOnStartup {
                blockchainName, partnerLogin, partnerAddress);

        try {
-            List<RemoteBlockchainSyncClient.RemoteBlockchainHead> heads = REMOTE.listBlockchainHeads(partnerAddress);
+            List<RemoteBlockchainSyncClient.RemoteBlockchainHead> heads =
+                    REMOTE.listBlockchainHeads(partnerLogin, partnerAddress);
            RemoteBlockchainSyncClient.RemoteBlockchainHead remoteHead = heads.stream()
                    .filter(h -> h != null && blockchainName.equals(h.blockchainName()))
                    .findFirst()
@@ -102,7 +102,7 @@ public final class PeriodicBlockchainSyncService {
        if (partnerLogin == null) return;

        List<RemoteBlockchainSyncClient.RemoteBlockchainHead> remoteHeads =
-                REMOTE.listBlockchainHeads(partner.getServerAddress());
+                REMOTE.listBlockchainHeads(partner.getLogin(), partner.getServerAddress());

        for (RemoteBlockchainSyncClient.RemoteBlockchainHead remoteHead : remoteHeads) {
            if (remoteHead == null || remoteHead.blockchainName() == null || remoteHead.blockchainName().isBlank()) {
@@ -170,7 +170,8 @@ public final class PeriodicBlockchainSyncService {
        int fromBlockNumber = Math.max(localLast + 1, 0);
        for (int blockNumber = fromBlockNumber; blockNumber <= remoteHead.lastBlockNumber(); blockNumber++) {
            RemoteBlockchainSyncClient.RemoteBlockchainBlock remoteBlock =
-                    REMOTE.getBlockchainBlock(partner.getServerAddress(), remoteHead.blockchainName(), blockNumber);
+                    REMOTE.getBlockchainBlock(
+                            partner.getLogin(), partner.getServerAddress(), remoteHead.blockchainName(), blockNumber);
            if (remoteBlock == null) {
                log.warn("Periodic blockchain sync: remote block not found. partner={} blockchainName={} blockNumber={}",
                        partnerLogin, remoteHead.blockchainName(), blockNumber);
@@ -284,7 +285,8 @@ public final class PeriodicBlockchainSyncService {
            String localPrevHash = "";
            for (int blockNumber = 0; blockNumber <= remoteHead.lastBlockNumber(); blockNumber++) {
                RemoteBlockchainSyncClient.RemoteBlockchainBlock remoteBlock =
-                        REMOTE.getBlockchainBlock(partner.getServerAddress(), blockchainName, blockNumber);
+                        REMOTE.getBlockchainBlock(
+                                partner.getLogin(), partner.getServerAddress(), blockchainName, blockNumber);
                if (remoteBlock == null) {
                    log.warn("Blockchain resync: remote block not found. partner={} blockchainName={} blockNumber={}",
                            partnerLogin, blockchainName, blockNumber);
@@ -137,7 +137,7 @@ public final class PeriodicUserSettingsSyncService {
        boolean bootstrapCompleted = false;

        int appliedDm;
-        try (RemoteSyncSession session = new RemoteSyncSession(route.getServerUrl())) {
+        try (RemoteSyncSession session = new RemoteSyncSession(route.getServerLogin(), route.getServerUrl())) {
        for (int page = 0; page < maxPages; page++) {
            RemoteUserSettingsSyncClient.RemoteUserSettingsBatch batch = REMOTE.userSettingsSyncBatch(
                    session,
@@ -83,3 +83,11 @@ WebSocket-эндпоинт для одного соединения.

 - `WsServer` = сервер, который слушает порт и вешает `/ws`.
 - `BlockchainWsEndpoint` = обработчик одного WebSocket-подключения, мост между сетью и логикой.
+
+## Постоянные server-to-server соединения
+
+Исходящие межсерверные JSON-запросы проходят через
+`server.sync.ServerConnectionPool`. Пул держит одно постоянное исходящее WSS-
+соединение на `serverLogin`, отправляет `ServerHello`, поддерживает канал через
+WebSocket ping/pong и переподключает его с backoff. DM, settings и blockchain
+используют это соединение с разными приоритетами, не меняя свою бизнес-логику.
@@ -12,6 +12,7 @@ import server.sync.PeriodicDmSyncService;
 import server.sync.PeriodicUserSettingsSyncService;
 import server.sync.SolanaUsersSyncStartupService;
 import server.sync.SyncServersBootstrapService;
+import server.sync.ServerConnectionPool;
 import utils.config.AppConfig;

 import java.time.Duration;
@@ -104,6 +105,10 @@ public final class WsServer {

        server.start();
        log.info("✅ WS сервер запущен на ws://localhost:{}/ws", port);
+        ServerConnectionPool.getInstance().startOrLog();
+        Runtime.getRuntime().addShutdownHook(new Thread(
+                () -> ServerConnectionPool.getInstance().close(),
+                "server-connection-pool-shutdown"));
        PeriodicDmSyncService.startOrLog();
        PeriodicUserSettingsSyncService.startOrLog();
        server.join();
@@ -41,6 +41,12 @@ dm.worker.dueLimit=100
 dm.sync.batchLimit=200
 dm.sync.batchMaxBytes=3000000
 dm.sync.maxPagesPerPeer=20
+server.pool.pingIdleSeconds=120
+server.pool.pongTimeoutSeconds=15
+server.pool.requestTimeoutSeconds=12
+server.pool.connectTimeoutSeconds=15
+server.pool.callerTimeoutSeconds=35
+server.pool.maxQueuePerPeer=2000
 server.info.url=
 server.info.physicalRegion=
 server.info.description=
@@ -1,3 +1,3 @@
 backup.schema.version=2
-backup.full.version=3
-last.full.backup.date=2026-08-08
+backup.full.version=4
+last.full.backup.date=2026-08-25
@@ -32,6 +32,7 @@
 | `CloseActiveSession` | `03_Session_Management_API.md` | закрытие активной сессии |
 | `AddBlock` | `04_Add_Block_to_Blockchain_API.md` | добавление блока в блокчейн |
 | `GetBlockchainBlock` | `04_Add_Block_to_Blockchain_API.md` | чтение одного блока блокчейна |
+| `ServerHello` | `16_Server_Connection_Pool_API.md` | объявление server-to-server соединения и возможностей peer без криптографической проверки |
 | `Ping` | `05_Technical_Requests_API.md` | keep-alive |
 | `GetServerInfo` | `05_Technical_Requests_API.md` | публичная информация о сервере |
 | `ListBlockchainHeads` | `05_Technical_Requests_API.md` | список heads всех локальных блокчейнов |
@@ -79,6 +80,7 @@

 - `ReceiveOutcomingMessage` зарегистрирован как алиас того же handler/request-класса, что и `SendMessagePair`, и сохраняет прежний межсерверный payload.
 - Межсерверные DM-операции пока доверяют `sourceServerLogin`; отдельная межсерверная авторизация запланирована позднее.
+- `ServerHello` пока принимает заявленный `serverLogin` на доверии и не является криптографической аутентификацией.
 - Отдельных HTTP endpoints для DM-файлов сейчас нет.
 - Классы `Net_MarkChannelMessagesSeen_*` существуют в коде, но операция `MarkChannelMessagesSeen` не зарегистрирована в `JsonHandlerRegistry`, поэтому в публичный список API не входит.
 - HTTP debug endpoints из `src/main/java/server/debug/` не входят в этот индекс WebSocket `op`; они описаны отдельно в `13_HTTP_Debug_API.md`.
@@ -83,7 +83,10 @@

 ## 5. Синхронизация

-Настройки и DM имеют раздельные таблицы и правила ACK, но периодический процесс открывает один последовательный WS-сеанс с peer: сначала синхронизирует настройки, затем забирает `DmSyncBatch`.
+Настройки и DM имеют раздельные таблицы и правила ACK, но периодический процесс
+использует один логический последовательный сеанс поверх постоянного WSS-пула:
+сначала синхронизирует настройки, затем забирает `DmSyncBatch`. Завершение
+логического сеанса не закрывает физический сокет.

 - локальная запись создаётся с `synced=false`, если её ещё не подтвердил второй сервер;
 - если запись пришла с другого сервера, она сохраняется сразу как `synced=true`;
@@ -183,16 +183,20 @@ Full resync запускается только тогда, когда:

 Настройка влияет именно на этап подготовки отсутствующей локальной цепочки во время periodic sync.

-## 5. Возможное развитие server-to-server транспорта
+## 5. Реализованный постоянный server-to-server транспорт

-Этот раздел не описывает текущую DM-доставку. DM уже использует короткие one-shot WebSocket-вызовы, indexed outbox и ACK. Ниже остаётся возможное развитие постоянного транспорта и server-auth.
+Этот раздел не меняет текущую семантику DM, settings и blockchain. Он описывает
+единый постоянный WSS-транспорт, через который выполняются уже существующие операции.

 ### 5.1 Межсерверное соединение

- Серверы устанавливают постоянное WebSocket-соединение друг с другом.
+- Серверы устанавливают постоянное исходящее WebSocket-соединение друг с другом.
 - Адрес партнёра определяется по `server_address` из его Solana PDA.
- Аутентификация: подпись Ed25519 корневым ключом сервера (`root_key` из PDA).
- При разрыве — переподключение с экспоненциальным backoff.
+- После подключения отправляется `ServerHello` с `serverLogin`, версией протокола и capabilities.
+- На текущем этапе `serverLogin` принимается на доверии; подпись Ed25519 корневым ключом сервера отложена.
+- При разрыве выполняется переподключение с jitter/backoff до 60 секунд.
+- После 120 секунд отсутствия полезного трафика отправляется WebSocket ping; pong ожидается 15 секунд.
+- Один физический канал переиспользуют DM, настройки и blockchain.

 ### 5.2 Доставка новых данных (push)

@@ -246,19 +250,21 @@ Full resync запускается только тогда, когда:
 | Плановый blockchain sync при старте + каждые 12 часов | ✅ Реализовано |
 | Обход Solana RPC через `sync.importUserProfileFromPartner.enabled` | ✅ Реализовано |
 | Обычный `AddBlock` через `tmp_bch`/`write_check`/`write_pending` | ✅ Реализовано |
-| Межсерверный постоянный WebSocket-канал | Нужна реализация |
+| Межсерверный постоянный WebSocket-канал | ✅ Реализован общий `ServerConnectionPool` |
 | Асинхронная доставка DM на access-серверы получателя | ✅ Реализовано |
 | Retry DM до 1 часа + UI-state | ✅ Реализовано |
 | Репликация DM на второй access-сервер по `synced` | ✅ Реализовано |
 | Read-only `GetDmDeliveryStatus` | ✅ Реализовано |
-| Push блоков блокчейна партнёрам | ✅ Реализована базовая one-shot версия |
+| Push блоков блокчейна партнёрам | ✅ Выполняется через постоянный WSS-пул |
 | Periodic backfill отсутствующего хвоста | ✅ Реализовано |
 | Разрешение рассинхрона / divergence | ✅ Реализована базовая full-resync схема во время periodic sync |
 | Startup recovery по `*.resync_pending` marker-file | ✅ Реализовано |
 | Маршрутизация DM через один/два `access_servers` | ✅ Реализовано |
 | Криптографическая server-to-server авторизация DM | Нужна реализация |

-Текущая версия сервера умеет синхронизацию блокчейнов и DM. Постоянные server-to-server соединения не требуются для текущей one-shot WS-реализации; отдельной будущей задачей остаётся криптографическая авторизация DM-вызовов.
+Текущая версия сервера использует постоянный WSS-пул для существующих
+server-to-server JSON-операций. Отдельной будущей задачей остаётся
+криптографическая авторизация server-to-server вызовов.

 Следующие отдельные шаги после текущего этапа:
 - отдельно проверить full-resync и startup-recovery на реальном тестовом прогоне после ручного удаления БД/файлов.