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test(spanner): deflake testCreateSessionDeadlineExceededWithNoSessionCreateWaitTime #14285

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test(spanner): deflake testCreateSessionDeadlineExceededWithNoSessionCreateWaitTime #14285

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test(spanner): deflake testCreateSessionDeadlineExceededWithNoSession…
sakthivelmanii Sep 7, 2026
0149042
test(spanner): move unfreeze inside ResultSet try block before result…
sakthivelmanii Sep 7, 2026
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23 changes: 14 additions & 9 deletions ...rc/test/java/com/google/cloud/spanner/MultiplexedSessionDatabaseClientMockServerTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -106,7 +106,7 @@ public void testCreateSessionDeadlineExceededWithNoSessionCreateWaitTime() throw
// Simulate a problem with the CreateSession RPC making it slow.
mockSpanner.setCreateSessionExecutionTime(
SimulatedExecutionTime.ofException(Status.DEADLINE_EXCEEDED.asRuntimeException()));
mockSpanner.freezeAfter(1);
mockSpanner.freeze();

Spanner testSpanner =
SpannerOptions.newBuilder()
Expand All @@ -119,17 +119,22 @@ public void testCreateSessionDeadlineExceededWithNoSessionCreateWaitTime() throw
DatabaseClientImpl client =
(DatabaseClientImpl) testSpanner.getDatabaseClient(DatabaseId.of("p", "i", "d"));

// The first attempt should lead to a DEADLINE_EXCEEDED error being propagated from the
// CreateSession attempt.
try (ResultSet resultSet = client.singleUse().executeQuery(STATEMENT)) {
SpannerException exception = assertThrows(SpannerException.class, resultSet::next);
assertEquals(ErrorCode.DEADLINE_EXCEEDED, exception.getErrorCode());
// Wait until the initial CreateSession request has reached the mock server and is frozen.
mockSpanner.waitForRequestsToContain(CreateSessionRequest.class, 5000);

// Acquire the transaction while the initial CreateSession request is in progress.
// This guarantees that this transaction binds to the initial (failing) attempt.
try (ReadContext readContext = client.singleUse()) {
// The first attempt should lead to a DEADLINE_EXCEEDED error being propagated from the
// CreateSession attempt.
try (ResultSet resultSet = readContext.executeQuery(STATEMENT)) {
mockSpanner.unfreeze();
SpannerException exception = assertThrows(SpannerException.class, resultSet::next);
assertEquals(ErrorCode.DEADLINE_EXCEEDED, exception.getErrorCode());
}
}
Comment on lines +127 to 135

@gemini-code-assist gemini-code-assist Bot Sep 7, 2026

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medium

Calling mockSpanner.unfreeze() before readContext.executeQuery(STATEMENT) introduces a potential race condition. If the mock server processes the unfrozen CreateSession request and the client receives the DEADLINE_EXCEEDED failure before executeQuery is executed, the client might clear the failed session attempt and initiate a new CreateSession request for the query. Since the simulated exception is not sticky, this new request would succeed, causing the test to fail.

To guarantee that the query binds to the initial failing attempt, we should call readContext.executeQuery(STATEMENT) while the server is still frozen, and then call mockSpanner.unfreeze() before calling resultSet.next() (which is where the blocking and exception propagation actually happen).

    try (ReadContext readContext = client.singleUse()) {
      // The first attempt should lead to a DEADLINE_EXCEEDED error being propagated from the
      // CreateSession attempt.
      try (ResultSet resultSet = readContext.executeQuery(STATEMENT)) {
        mockSpanner.unfreeze();
        SpannerException exception = assertThrows(SpannerException.class, resultSet::next);
        assertEquals(ErrorCode.DEADLINE_EXCEEDED, exception.getErrorCode());
      }
    }

@sakthivelmanii sakthivelmanii Sep 7, 2026

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Done


// The next attempt should then succeed.
mockSpanner.unfreeze();
assertNotNull(client.multiplexedSessionDatabaseClient.getCurrentSessionReference());

try (ResultSet resultSet = client.singleUse().executeQuery(STATEMENT)) {
//noinspection StatementWithEmptyBody
while (resultSet.next()) {}
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