feat(mysql): terminate sessions from the process list

apps/desktop/src/lib/__tests__/database/mysqlProcessList.spec.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from "vitest";
 import type { QueryResult } from "@/types/database";
-import { buildCancelQuerySql, clampInterval, createProcessListLoadCoordinator, mapProcessRows, processListExecutionError, processListSessionCount, supportsProcessList } from "@/lib/database/mysqlProcessList";
+import { buildCancelQuerySql, buildTerminateSessionSql, clampInterval, createProcessListLoadCoordinator, mapProcessRows, processListExecutionError, processListSessionCount, supportsProcessList } from "@/lib/database/mysqlProcessList";
 
 function result(columns: string[], rows: (string | number | boolean | null)[][]): QueryResult {
   return { columns, rows, affected_rows: 0, execution_time_ms: 0 };
@@ -48,6 +48,19 @@ describe("buildCancelQuerySql", () => {
   });
 });
 
+describe("buildTerminateSessionSql", () => {
+  it("builds KILL for a valid id so an idle session is really disconnected", () => {
+    expect(buildTerminateSessionSql(8213)).toBe("KILL 8213");
+  });
+
+  it("rejects non-integer or nonpositive ids", () => {
+    expect(() => buildTerminateSessionSql(1.5)).toThrow();
+    expect(() => buildTerminateSessionSql(0)).toThrow();
+    expect(() => buildTerminateSessionSql(-1)).toThrow();
+    expect(() => buildTerminateSessionSql(Number.NaN)).toThrow();
+  });
+});
+
 describe("clampInterval", () => {
   it("clamps below the minimum to 1 second", () => {
     expect(clampInterval(0)).toBe(1);

apps/desktop/src/lib/__tests__/database/postgresProcessList.spec.ts

@@ -3,10 +3,14 @@ import type { QueryResult } from "@/types/database";
 import {
   buildKingbaseCancelQuerySql,
   buildKingbasePgCancelQuerySql,
+  buildKingbasePgTerminateSessionSql,
+  buildKingbaseTerminateSessionSql,
   buildPgCancelQuerySql,
+  buildPgTerminateSessionSql,
   isKingbaseOwnSessionCatalogCompatibilityError,
   isKingbaseProcessListCatalogCompatibilityError,
   isKingbaseCancelCatalogCompatibilityError,
+  isKingbaseTerminateCatalogCompatibilityError,
   isPgProcessListCompatibilityError,
   KINGBASE_OWN_SESSION_SQL,
   KINGBASE_PG_OWN_SESSION_SQL,
@@ -18,6 +22,7 @@ import {
   kingbaseCancelQueryResultError,
   kingbasePgCancelQueryResultError,
   pgCancelQueryResultError,
+  pgTerminateSessionResultError,
   PG_PROCESS_LIST_LEGACY_SQL,
   PG_PROCESS_LIST_SQL,
 } from "@/lib/database/postgresProcessList";
@@ -120,6 +125,32 @@ describe("PostgreSQL-family process SQL", () => {
   });
 });
 
+describe("session termination statements", () => {
+  it("builds pg_terminate_backend so an idle backend is really disconnected", () => {
+    expect(buildPgTerminateSessionSql(4211)).toBe("SELECT pg_terminate_backend(4211)");
+    expect(buildKingbaseTerminateSessionSql(4211)).toBe("SELECT sys_terminate_backend(4211)");
+    expect(buildKingbasePgTerminateSessionSql(4211)).toBe("SELECT pg_terminate_backend(4211)");
+  });
+
+  it("rejects non-integer or nonpositive pids", () => {
+    expect(() => buildPgTerminateSessionSql(1.5)).toThrow();
+    expect(() => buildPgTerminateSessionSql(0)).toThrow();
+    expect(() => buildPgTerminateSessionSql(Number.NaN)).toThrow();
+  });
+
+  it("requires the server to confirm that a backend was terminated", () => {
+    expect(pgTerminateSessionResultError([result(["pg_terminate_backend"], [[true]])])).toBeNull();
+    expect(pgTerminateSessionResultError([result(["pg_terminate_backend"], [["t"]])])).toBeNull();
+    expect(pgTerminateSessionResultError([result(["pg_terminate_backend"], [[false]])])).toContain("did not terminate");
+    expect(pgTerminateSessionResultError([result(["pg_terminate_backend"], [])])).toContain("did not terminate");
+  });
+
+  it("detects the Kingbase fallback trigger for a missing sys_terminate_backend", () => {
+    expect(isKingbaseTerminateCatalogCompatibilityError(new Error("function sys_terminate_backend(integer) does not exist"))).toBe(true);
+    expect(isKingbaseTerminateCatalogCompatibilityError(new Error("permission denied"))).toBe(false);
+  });
+});
+
 describe("Postgres compatibility", () => {
   it("provides a pre-9.6 query and only falls back for missing wait-event columns", () => {
     expect(PG_PROCESS_LIST_SQL).toContain("wait_event_type");
@@ -145,7 +176,10 @@ describe("resolveProcessListDriver", () => {
     const mysql = resolveProcessListDriver("mysql");
     const postgres = resolveProcessListDriver("postgres");
     expect(mysql?.buildCancelQuerySql(7)).toBe("KILL QUERY 7");
+    expect(mysql?.buildTerminateSessionSql?.(7)).toBe("KILL 7");
     expect(postgres?.buildCancelQuerySql(7)).toBe("SELECT pg_cancel_backend(7)");
+    expect(postgres?.buildTerminateSessionSql?.(7)).toBe("SELECT pg_terminate_backend(7)");
+    expect(postgres?.terminateSessionResultError?.([result(["pg_terminate_backend"], [[false]])])).toContain("did not terminate");
     expect(postgres?.fallbackListSql).toBe(PG_PROCESS_LIST_LEGACY_SQL);
     expect(postgres?.shouldUseFallbackListSql?.(new Error('column "wait_event" does not exist'))).toBe(true);
     expect(postgres?.cancelQueryResultError?.([result(["pg_cancel_backend"], [[false]])])).toContain("did not cancel");
@@ -177,6 +211,8 @@ describe("connectionSupportsProcessList", () => {
     expect(connectionSupportsProcessList(conn({ db_type: "gaussdb", driver_profile: "opengauss" }))).toBe(true);
     expect(connectionSupportsProcessList(conn({ db_type: "gaussdb", driver_profile: "gaussdb" }))).toBe(false);
     expect(connectionSupportsProcessList(conn({ db_type: "kingbase" }))).toBe(true);
+    expect(resolveProcessListDriver("kingbase")?.buildTerminateSessionSql?.(7)).toBe("SELECT sys_terminate_backend(7)");
+    expect(resolveProcessListDriver("opengauss")?.buildTerminateSessionSql?.(7)).toBe("SELECT pg_terminate_backend(7)");
     expect(connectionSupportsProcessList(conn({ db_type: "sqlite" }))).toBe(false);
     expect(connectionSupportsProcessList(undefined)).toBe(false);
   });

apps/desktop/src/lib/database/mysqlProcessList.ts

@@ -137,6 +137,21 @@ export function buildCancelQuerySql(id: number): string {
   return `KILL QUERY ${id}`;
 }
 
+/**
+ * Build the `KILL <id>` statement that disconnects the session itself.
+ *
+ * `KILL QUERY` only interrupts the statement running at that instant, so an idle
+ * (`Sleep`) session survives it and keeps showing up in the process list. When the
+ * user asks to close a session, only this statement actually removes it (and rolls
+ * back the session's uncommitted transaction, the same as the server-side `KILL`).
+ */
+export function buildTerminateSessionSql(id: number): string {
+  if (!Number.isInteger(id) || id <= 0) {
+    throw new Error(`Invalid session id: ${id}`);
+  }
+  return `KILL ${id}`;
+}
+
 /** Clamp a user-entered refresh interval to a safe integer range of seconds. */
 export function clampInterval(seconds: number): number {
   if (!Number.isFinite(seconds)) return DEFAULT_REFRESH_SECONDS;

apps/desktop/src/lib/database/postgresProcessList.ts

@@ -174,6 +174,27 @@ export function buildKingbasePgCancelQuerySql(pid: number): string {
   return `SELECT pg_cancel_backend(${pid})`;
 }
 
+/**
+ * Build the statement that disconnects the backend instead of only interrupting the
+ * statement it is running right now. `pg_cancel_backend` cancels the current query and
+ * leaves an idle backend alive, so the process list keeps listing it; terminating the
+ * backend is what actually removes the session (rolling back its open transaction).
+ */
+export function buildPgTerminateSessionSql(pid: number): string {
+  validateBackendPid(pid);
+  return `SELECT pg_terminate_backend(${pid})`;
+}
+
+export function buildKingbaseTerminateSessionSql(pid: number): string {
+  validateBackendPid(pid);
+  return `SELECT sys_terminate_backend(${pid})`;
+}
+
+export function buildKingbasePgTerminateSessionSql(pid: number): string {
+  validateBackendPid(pid);
+  return `SELECT pg_terminate_backend(${pid})`;
+}
+
 /** Return an error when PostgreSQL reports that no running query was canceled. */
 export function pgCancelQueryResultError(results: QueryResult[]): string | null {
   return backendCancelQueryResultError(results, "pg_cancel_backend");
@@ -187,11 +208,24 @@ export function kingbasePgCancelQueryResultError(results: QueryResult[]): string
   return backendCancelQueryResultError(results, "pg_cancel_backend");
 }
 
-function backendCancelQueryResultError(results: QueryResult[], functionName: string): string | null {
+/** Return an error when the server reports that no backend was terminated. */
+export function pgTerminateSessionResultError(results: QueryResult[]): string | null {
+  return backendCancelQueryResultError(results, "pg_terminate_backend", "did not terminate the session");
+}
+
+export function kingbaseTerminateSessionResultError(results: QueryResult[]): string | null {
+  return backendCancelQueryResultError(results, "sys_terminate_backend", "did not terminate the session");
+}
+
+export function kingbasePgTerminateSessionResultError(results: QueryResult[]): string | null {
+  return backendCancelQueryResultError(results, "pg_terminate_backend", "did not terminate the session");
+}
+
+function backendCancelQueryResultError(results: QueryResult[], functionName: string, failure = "did not cancel a running query"): string | null {
   const result = results.find((item) => item.execution_error !== true);
   const value = result?.rows?.[0]?.[0];
   if (value === true || value === 1 || String(value).toLowerCase() === "t" || String(value).toLowerCase() === "true") return null;
-  return `${functionName} did not cancel a running query`;
+  return `${functionName} ${failure}`;
 }
 
 /** Detect the undefined-column failure produced by pre-9.6 pg_stat_activity. */
@@ -213,3 +247,7 @@ export function isKingbaseOwnSessionCatalogCompatibilityError(error: unknown): b
 export function isKingbaseCancelCatalogCompatibilityError(error: unknown): boolean {
   return isMissingKingbaseSysFunction(error, ["sys_cancel_backend"]);
 }
+
+export function isKingbaseTerminateCatalogCompatibilityError(error: unknown): boolean {
+  return isMissingKingbaseSysFunction(error, ["sys_terminate_backend"]);
+}

apps/desktop/src/lib/database/processListDrivers.ts

@@ -1,16 +1,22 @@
 import type { ConnectionConfig, DatabaseType, QueryResult } from "@/types/database";
 import { effectiveDatabaseTypeForConnection } from "@/lib/database/jdbcDialect";
-import { buildCancelQuerySql as buildMysqlCancelQuerySql, mapProcessRows as mapMysqlProcessRows, PROCESS_LIST_SQL as MYSQL_PROCESS_LIST_SQL, supportsProcessList as supportsMysqlProcessList } from "./mysqlProcessList";
+import { buildCancelQuerySql as buildMysqlCancelQuerySql, buildTerminateSessionSql as buildMysqlTerminateSessionSql, mapProcessRows as mapMysqlProcessRows, PROCESS_LIST_SQL as MYSQL_PROCESS_LIST_SQL, supportsProcessList as supportsMysqlProcessList } from "./mysqlProcessList";
 import {
   buildKingbaseCancelQuerySql,
   buildKingbasePgCancelQuerySql,
+  buildKingbasePgTerminateSessionSql,
+  buildKingbaseTerminateSessionSql,
   buildPgCancelQuerySql,
+  buildPgTerminateSessionSql,
   isKingbaseOwnSessionCatalogCompatibilityError,
   isKingbaseProcessListCatalogCompatibilityError,
   isKingbaseCancelCatalogCompatibilityError,
+  isKingbaseTerminateCatalogCompatibilityError,
   isPgProcessListCompatibilityError,
   kingbaseCancelQueryResultError,
   kingbasePgCancelQueryResultError,
+  kingbasePgTerminateSessionResultError,
+  kingbaseTerminateSessionResultError,
   KINGBASE_OWN_SESSION_SQL,
   KINGBASE_PG_OWN_SESSION_SQL,
   KINGBASE_PG_PROCESS_LIST_SQL,
@@ -19,6 +25,7 @@ import {
   OPENGAUSS_OWN_SESSION_SQL,
   OPENGAUSS_PROCESS_LIST_SQL,
   pgCancelQueryResultError,
+  pgTerminateSessionResultError,
   PG_OWN_SESSION_SQL,
   PG_PROCESS_LIST_LEGACY_SQL,
   PG_PROCESS_LIST_SQL,
@@ -79,6 +86,19 @@ export interface ProcessListDriver {
   cancelQueryResultError?(results: QueryResult[]): string | null;
   /** Validate the success value returned by the compatibility cancellation statement. */
   fallbackCancelQueryResultError?(results: QueryResult[]): string | null;
+  /**
+   * Build the validated statement that disconnects the session. Engines that omit it
+   * only offer query cancellation, because they cannot close a session over the wire.
+   */
+  buildTerminateSessionSql?(id: number): string;
+  /** Build the compatibility statement used when the primary terminate function is unavailable. */
+  buildFallbackTerminateSessionSql?(id: number): string;
+  /** Restrict terminate fallback attempts to known compatibility failures. */
+  shouldUseFallbackTerminateSessionSql?(error: unknown): boolean;
+  /** Validate any engine-specific success value returned by the terminate statement. */
+  terminateSessionResultError?(results: QueryResult[]): string | null;
+  /** Validate the success value returned by the compatibility terminate statement. */
+  fallbackTerminateSessionResultError?(results: QueryResult[]): string | null;
 }
 
 const MYSQL_COLUMNS: ProcessColumn[] = [
@@ -114,6 +134,7 @@ const MYSQL_DRIVER: ProcessListDriver = {
   // Typed structs carry no index signature; they are plain string-keyed objects at runtime.
   mapRows: (result) => mapMysqlProcessRows(result) as unknown as ProcessRow[],
   buildCancelQuerySql: buildMysqlCancelQuerySql,
+  buildTerminateSessionSql: buildMysqlTerminateSessionSql,
 };
 
 const POSTGRES_DRIVER: ProcessListDriver = {
@@ -127,6 +148,8 @@ const POSTGRES_DRIVER: ProcessListDriver = {
   mapRows: (result) => mapPgProcessRows(result) as unknown as ProcessRow[],
   buildCancelQuerySql: buildPgCancelQuerySql,
   cancelQueryResultError: pgCancelQueryResultError,
+  buildTerminateSessionSql: buildPgTerminateSessionSql,
+  terminateSessionResultError: pgTerminateSessionResultError,
 };
 
 const OPENGAUSS_DRIVER: ProcessListDriver = {
@@ -138,6 +161,8 @@ const OPENGAUSS_DRIVER: ProcessListDriver = {
   mapRows: (result) => mapPgProcessRows(result) as unknown as ProcessRow[],
   buildCancelQuerySql: buildPgCancelQuerySql,
   cancelQueryResultError: pgCancelQueryResultError,
+  buildTerminateSessionSql: buildPgTerminateSessionSql,
+  terminateSessionResultError: pgTerminateSessionResultError,
 };
 
 const KINGBASE_DRIVER: ProcessListDriver = {
@@ -156,6 +181,11 @@ const KINGBASE_DRIVER: ProcessListDriver = {
   shouldUseFallbackCancelQuerySql: isKingbaseCancelCatalogCompatibilityError,
   cancelQueryResultError: kingbaseCancelQueryResultError,
   fallbackCancelQueryResultError: kingbasePgCancelQueryResultError,
+  buildTerminateSessionSql: buildKingbaseTerminateSessionSql,
+  buildFallbackTerminateSessionSql: buildKingbasePgTerminateSessionSql,
+  shouldUseFallbackTerminateSessionSql: isKingbaseTerminateCatalogCompatibilityError,
+  terminateSessionResultError: kingbaseTerminateSessionResultError,
+  fallbackTerminateSessionResultError: kingbasePgTerminateSessionResultError,
 };
 
 /** Resolve the process-list driver for a connection, or null if unsupported. */