fix: revert using GetSession as ping

Author: olavloite

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

@@ -101,10 +101,6 @@ public String getName() {
  return options;
  }
 
- com.google.spanner.v1.Session get() {
- return spanner.getRpc().getSession(name);
- }
-
  @Override
  public long executePartitionedUpdate(Statement stmt) {
  setActive(null);

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

@@ -841,7 +841,12 @@ public void prepareReadWriteTransaction() {
 
  private void keepAlive() {
  markUsed();
- delegate.get();
+ try (ResultSet resultSet =
+ delegate
+ .singleUse(TimestampBound.ofMaxStaleness(60, TimeUnit.SECONDS))
+ .executeQuery(Statement.newBuilder("SELECT 1").build())) {
+ resultSet.next();
+ }
  }
 
  void markUsed() {

google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GapicSpannerRpc.java

@@ -109,7 +109,6 @@
 import com.google.spanner.v1.ExecuteBatchDmlRequest;
 import com.google.spanner.v1.ExecuteBatchDmlResponse;
 import com.google.spanner.v1.ExecuteSqlRequest;
-import com.google.spanner.v1.GetSessionRequest;
 import com.google.spanner.v1.PartialResultSet;
 import com.google.spanner.v1.PartitionQueryRequest;
 import com.google.spanner.v1.PartitionReadRequest;
@@ -345,13 +344,6 @@ private void acquireAdministrativeRequestsRateLimiter() {
  }
  }
 
- @Override
- public Session getSession(String name) {
- GetSessionRequest request = GetSessionRequest.newBuilder().setName(name).build();
- GrpcCallContext context = newCallContext(null, projectName);
- return get(spannerStub.getSessionCallable().futureCall(request, context));
- }
-
  @Override
  public Paginated<InstanceConfig> listInstanceConfigs(int pageSize, @Nullable String pageToken)
  throws SpannerException {

google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/SpannerRpc.java

@@ -172,8 +172,6 @@ interface StreamingCall {
  void cancel(@Nullable String message);
  }
 
- Session getSession(String name);
-
  // Instance admin APIs.
  Paginated<InstanceConfig> listInstanceConfigs(int pageSize, @Nullable String pageToken)
  throws SpannerException;

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

@@ -19,6 +19,7 @@
 import static com.google.common.truth.Truth.assertThat;
 import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 import static org.mockito.MockitoAnnotations.initMocks;
 
@@ -99,20 +100,23 @@ public void run() {
  }
 
  private SessionImpl setupMockSession(final SessionImpl session) {
- when(session.get())
+ ReadContext mockContext = mock(ReadContext.class);
+ final ResultSet mockResult = mock(ResultSet.class);
+ when(session.singleUse(any(TimestampBound.class))).thenReturn(mockContext);
+ when(mockContext.executeQuery(any(Statement.class)))
  .thenAnswer(
- new Answer<com.google.spanner.v1.Session>() {
+ new Answer<ResultSet>() {
  @Override
- public com.google.spanner.v1.Session answer(InvocationOnMock invocation)
- throws Throwable {
+ public ResultSet answer(InvocationOnMock invocation) throws Throwable {
  Integer currentValue = pingedSessions.get(session.getName());
  if (currentValue == null) {
  currentValue = 0;
  }
  pingedSessions.put(session.getName(), ++currentValue);
- return com.google.spanner.v1.Session.getDefaultInstance();
+ return mockResult;
  }
  });
+ when(mockResult.next()).thenReturn(true);
  return session;
  }
 

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

@@ -17,6 +17,7 @@
 package com.google.cloud.spanner;
 
 import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -142,16 +143,20 @@ public Void answer(InvocationOnMock invocation) throws Throwable {
  }
 
  private void setupSession(final SessionImpl session) {
- when(session.get())
+ ReadContext mockContext = mock(ReadContext.class);
+ final ResultSet mockResult = mock(ResultSet.class);
+ when(session.singleUse(any(TimestampBound.class))).thenReturn(mockContext);
+ when(mockContext.executeQuery(any(Statement.class)))
  .thenAnswer(
- new Answer<com.google.spanner.v1.Session>() {
+ new Answer<ResultSet>() {
+
  @Override
- public com.google.spanner.v1.Session answer(InvocationOnMock invocation)
- throws Throwable {
+ public ResultSet answer(InvocationOnMock invocation) throws Throwable {
  resetTransaction(session);
- return com.google.spanner.v1.Session.getDefaultInstance();
+ return mockResult;
  }
  });
+ when(mockResult.next()).thenReturn(true);
  doAnswer(
  new Answer<ApiFuture<Empty>>() {
 

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

@@ -892,8 +892,8 @@ public void run() {
  })
  .when(sessionClient)
  .asyncBatchCreateSessions(Mockito.eq(1), Mockito.anyBoolean(), any(SessionConsumer.class));
- for (SessionImpl sess : new SessionImpl[] {session1, session2, session3}) {
- when(sess.get()).thenReturn(com.google.spanner.v1.Session.getDefaultInstance());
+ for (SessionImpl session : sessions) {
+ mockKeepAlive(session);
  }
  FakeClock clock = new FakeClock();
  clock.currentTimeMillis = System.currentTimeMillis();
@@ -963,16 +963,18 @@ public void run() {
  session1.close();
  session2.close();
  runMaintainanceLoop(clock, pool, pool.poolMaintainer.numKeepAliveCycles);
- verify(session, never()).get();
+ verify(session, never()).singleUse(any(TimestampBound.class));
  runMaintainanceLoop(clock, pool, pool.poolMaintainer.numKeepAliveCycles);
- verify(session, times(2)).get();
+ verify(session, times(2)).singleUse(any(TimestampBound.class));
  clock.currentTimeMillis +=
  clock.currentTimeMillis + (options.getKeepAliveIntervalMinutes() + 5) * 60 * 1000;
  session1 = pool.getReadSession();
  session1.writeAtLeastOnce(new ArrayList<Mutation>());
  session1.close();
  runMaintainanceLoop(clock, pool, pool.poolMaintainer.numKeepAliveCycles);
- verify(session, times(options.getMinSessions())).get();
+ // The session pool only keeps MinSessions + MaxIdleSessions alive.
+ verify(session, times(options.getMinSessions() + options.getMaxIdleSessions()))
+ .singleUse(any(TimestampBound.class));
  pool.closeAsync().get(5L, TimeUnit.SECONDS);
  }
 
@@ -1642,6 +1644,7 @@ public Void call() {
  private void mockKeepAlive(Session session) {
  ReadContext context = mock(ReadContext.class);
  ResultSet resultSet = mock(ResultSet.class);
+ when(resultSet.next()).thenReturn(true, false);
  when(session.singleUse(any(TimestampBound.class))).thenReturn(context);
  when(context.executeQuery(any(Statement.class))).thenReturn(resultSet);
  }