feat: long running transaction clean up background task. Adding configuration options for closing inactive transactions.

google-cloud-spanner/src/main/java/com/google/cloud/spanner/SessionPool.java

@@ -1891,11 +1891,23 @@ private void removeLongRunningSessions(
                     > 0) {
               if ((options.warnInactiveTransactions() || options.warnAndCloseInactiveTransactions())
                   && !session.isLeakedExceptionLogged) {
-                logger.log(
-                    Level.WARNING,
-                    String.format("Removing long running session => %s", session.getName()),
-                    sessionFuture.leakedException);
-                session.isLeakedExceptionLogged = true;
+                if (options.warnAndCloseInactiveTransactions()) {
+                  logger.log(
+                      Level.WARNING,
+                      String.format("Removing long-running session => %s", session.getName()),
+                      sessionFuture.leakedException);
+                  session.isLeakedExceptionLogged = true;
+                } else if (options.warnInactiveTransactions()) {
+                  logger.log(
+                      Level.WARNING,
+                      String.format(
+                          "Detected long-running session => %s. To automatically remove "
+                              + "long-running sessions, set SessionOption ActionOnInactiveTransaction "
+                              + "to WARN_AND_CLOSE by invoking setWarnAndCloseIfInactiveTransactions() method.",
+                          session.getName()),
+                      sessionFuture.leakedException);
+                  session.isLeakedExceptionLogged = true;
+                }
               }
               if ((options.closeInactiveTransactions()
                       || options.warnAndCloseInactiveTransactions())

google-cloud-spanner/src/main/java/com/google/cloud/spanner/SessionPoolOptions.java

@@ -334,8 +334,7 @@ static InactiveTransactionRemovalOptions.Builder newBuilder() {
     }
 
     static class Builder {
-      private ActionOnInactiveTransaction actionOnInactiveTransaction =
-          ActionOnInactiveTransaction.WARN;
+      private ActionOnInactiveTransaction actionOnInactiveTransaction;
       private Duration executionFrequency = Duration.ofMinutes(2);
       private double usedSessionsRatioThreshold = 0.95;
       private Duration idleTimeThreshold = Duration.ofMinutes(60L);
@@ -556,7 +555,7 @@ public Builder setBlockIfPoolExhausted() {
      *
      * @return this builder for chaining
      */
-    public Builder setWarnIfInactiveTransactions() {
+    Builder setWarnIfInactiveTransactions() {
       this.inactiveTransactionRemovalOptions =
           InactiveTransactionRemovalOptions.newBuilder()
               .setActionOnInactiveTransaction(ActionOnInactiveTransaction.WARN)
@@ -575,7 +574,7 @@ public Builder setWarnIfInactiveTransactions() {
      *
      * @return this builder for chaining
      */
-    public Builder setWarnAndCloseIfInactiveTransactions() {
+    Builder setWarnAndCloseIfInactiveTransactions() {
       this.inactiveTransactionRemovalOptions =
           InactiveTransactionRemovalOptions.newBuilder()
               .setActionOnInactiveTransaction(ActionOnInactiveTransaction.WARN_AND_CLOSE)

google-cloud-spanner/src/test/java/com/google/cloud/spanner/LongRunningSessionsBenchmark.java

@@ -202,7 +202,8 @@ public void burstWrite(final BenchmarkState server) throws Exception {
     }
     Futures.allAsList(futures).get();
     service.shutdown();
-    assertThat(pool.numLeakedSessionsRemoved()).isEqualTo(0); // no sessions should be cleaned up in case of partitioned updates.
+    assertThat(pool.numLeakedSessionsRemoved())
+        .isEqualTo(0); // no sessions should be cleaned up in case of partitioned updates.
   }
 
   /** Measures the time needed to execute a burst of read and write requests. */
@@ -249,31 +250,36 @@ public void burstReadAndWrite(final BenchmarkState server) throws Exception {
   }
 
   private void randomWait() throws InterruptedException {
-    if(RND.nextBoolean()) {
+    if (RND.nextBoolean()) {
       Thread.sleep(RND.nextInt(LONG_HOLD_SESSION_TIME));
     } else {
       Thread.sleep(RND.nextInt(HOLD_SESSION_TIME));
     }
   }
 
   private void randomWaitForMockServer(final BenchmarkState server) {
-    if(RND.nextBoolean()) {
-      server.mockServer.getMockSpanner().setExecuteStreamingSqlExecutionTime(
-          SimulatedExecutionTime.ofMinimumAndRandomTime(
-              LONG_HOLD_SESSION_TIME, 0));
+    if (RND.nextBoolean()) {
+      server
+          .mockServer
+          .getMockSpanner()
+          .setExecuteStreamingSqlExecutionTime(
+              SimulatedExecutionTime.ofMinimumAndRandomTime(LONG_HOLD_SESSION_TIME, 0));
     } else {
-      server.mockServer.getMockSpanner().setExecuteStreamingSqlExecutionTime(
-          SimulatedExecutionTime.ofMinimumAndRandomTime(
-              HOLD_SESSION_TIME, 0));
+      server
+          .mockServer
+          .getMockSpanner()
+          .setExecuteStreamingSqlExecutionTime(
+              SimulatedExecutionTime.ofMinimumAndRandomTime(HOLD_SESSION_TIME, 0));
     }
   }
 
   private void assertNumLeakedSessionsRemoved(final BenchmarkState server, final SessionPool pool) {
     final SessionPoolOptions sessionPoolOptions =
         server.spanner.getOptions().getSessionPoolOptions();
-    if(sessionPoolOptions.warnAndCloseInactiveTransactions() || sessionPoolOptions.closeInactiveTransactions()) {
+    if (sessionPoolOptions.warnAndCloseInactiveTransactions()
+        || sessionPoolOptions.closeInactiveTransactions()) {
       assertThat(pool.numLeakedSessionsRemoved()).isGreaterThan(0);
-    } else if(sessionPoolOptions.warnInactiveTransactions()) {
+    } else if (sessionPoolOptions.warnInactiveTransactions()) {
       assertThat(pool.numLeakedSessionsRemoved()).isEqualTo(0);
     }
   }

google-cloud-spanner/src/test/java/com/google/cloud/spanner/SessionPoolOptionsTest.java

@@ -129,7 +129,7 @@ public void verifyDefaultInactiveTransactionRemovalOptions() {
     InactiveTransactionRemovalOptions inactiveTransactionRemovalOptions =
         sessionPoolOptions.getInactiveTransactionRemovalOptions();
 
-    assertTrue(sessionPoolOptions.warnInactiveTransactions());
+    assertFalse(sessionPoolOptions.warnInactiveTransactions());
     assertFalse(sessionPoolOptions.warnAndCloseInactiveTransactions());
     assertFalse(sessionPoolOptions.closeInactiveTransactions());
     assertEquals(0.95, inactiveTransactionRemovalOptions.getUsedSessionsRatioThreshold(), 0.0);