feat: add opt-in for using multiplexed sessions for blind writes (googleapis#3540)

* feat(spanner): Releasing Multiplexed session for blind write.

* fix(spanner): Added exception for `setUseMultiplexedSessionBlindWrite` in Clirr check. Removing this is safe as it's not used by customers.

* fix(spanner): Fixed unit test for multiplexed session.

Author: pratickchokhani

google-cloud-spanner-executor/clirr-ignored-differences.xml

@@ -7,4 +7,9 @@
     <method>CloudExecutorImpl(boolean)</method>
     <to>CloudExecutorImpl(boolean, double)</to>
   </difference>
+  <difference>
+    <differenceType>7002</differenceType>
+    <className>com/google/cloud/spanner/SessionPoolOptionsHelper</className>
+    <method>com.google.cloud.spanner.SessionPoolOptions$Builder setUseMultiplexedSessionBlindWrite(com.google.cloud.spanner.SessionPoolOptions$Builder, boolean)</method>
+  </difference>
 </differences>

google-cloud-spanner-executor/src/main/java/com/google/cloud/executor/spanner/CloudClientExecutor.java

@@ -830,8 +830,6 @@ private synchronized Spanner getClient(long timeoutSeconds, boolean useMultiplex
     com.google.cloud.spanner.SessionPoolOptions.Builder poolOptionsBuilder =
         com.google.cloud.spanner.SessionPoolOptions.newBuilder();
     SessionPoolOptionsHelper.setUseMultiplexedSession(poolOptionsBuilder, useMultiplexedSession);
-    SessionPoolOptionsHelper.setUseMultiplexedSessionBlindWrite(
-        poolOptionsBuilder, useMultiplexedSession);
     SessionPoolOptionsHelper.setUseMultiplexedSessionForRW(
         poolOptionsBuilder, useMultiplexedSession);
     LOGGER.log(

google-cloud-spanner-executor/src/main/java/com/google/cloud/spanner/SessionPoolOptionsHelper.java

@@ -31,14 +31,6 @@ public static SessionPoolOptions.Builder setUseMultiplexedSession(
     return sessionPoolOptionsBuilder.setUseMultiplexedSession(useMultiplexedSession);
   }
 
-  // TODO: Remove when multiplexed session for blind write is released.
-  public static SessionPoolOptions.Builder setUseMultiplexedSessionBlindWrite(
-      SessionPoolOptions.Builder sessionPoolOptionsBuilder,
-      boolean useMultiplexedSessionBlindWrite) {
-    return sessionPoolOptionsBuilder.setUseMultiplexedSessionBlindWrite(
-        useMultiplexedSessionBlindWrite);
-  }
-
   // TODO: Remove when multiplexed session for read write is released.
   public static SessionPoolOptions.Builder setUseMultiplexedSessionForRW(
       SessionPoolOptions.Builder sessionPoolOptionsBuilder, boolean useMultiplexedSessionForRW) {

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

@@ -77,12 +77,6 @@ public class SessionPoolOptions {
 
   private final boolean useMultiplexedSession;
 
-  /**
-   * Controls whether multiplexed session is enabled for blind write or not. This is only used for
-   * systest soak. TODO: Remove when multiplexed session for blind write is released.
-   */
-  private final boolean useMultiplexedSessionBlindWrite;
-
   private final boolean useMultiplexedSessionForRW;
 
   private final boolean useMultiplexedSessionForPartitionedOps;
@@ -122,7 +116,6 @@ private SessionPoolOptions(Builder builder) {
         (useMultiplexedSessionFromEnvVariable != null)
             ? useMultiplexedSessionFromEnvVariable
             : builder.useMultiplexedSession;
-    this.useMultiplexedSessionBlindWrite = builder.useMultiplexedSessionBlindWrite;
     // useMultiplexedSessionForRW priority => Environment var > private setter > client default
     Boolean useMultiplexedSessionForRWFromEnvVariable =
         getUseMultiplexedSessionForRWFromEnvVariable();
@@ -205,7 +198,6 @@ public int hashCode() {
         this.inactiveTransactionRemovalOptions,
         this.poolMaintainerClock,
         this.useMultiplexedSession,
-        this.useMultiplexedSessionBlindWrite,
         this.useMultiplexedSessionForRW,
         this.multiplexedSessionMaintenanceDuration);
   }
@@ -349,7 +341,7 @@ public boolean getUseMultiplexedSession() {
   @VisibleForTesting
   @InternalApi
   protected boolean getUseMultiplexedSessionBlindWrite() {
-    return getUseMultiplexedSession() && useMultiplexedSessionBlindWrite;
+    return getUseMultiplexedSession();
   }
 
   @VisibleForTesting
@@ -601,9 +593,6 @@ public static class Builder {
     // Set useMultiplexedSession to true to make multiplexed session the default.
     private boolean useMultiplexedSession = false;
 
-    // TODO: Remove when multiplexed session for blind write is released.
-    private boolean useMultiplexedSessionBlindWrite = false;
-
     // This field controls the default behavior of session management for RW operations in Java
     // client.
     // Set useMultiplexedSessionForRW to true to make multiplexed session for RW operations the
@@ -657,7 +646,6 @@ private Builder(SessionPoolOptions options) {
       this.randomizePositionQPSThreshold = options.randomizePositionQPSThreshold;
       this.inactiveTransactionRemovalOptions = options.inactiveTransactionRemovalOptions;
       this.useMultiplexedSession = options.useMultiplexedSession;
-      this.useMultiplexedSessionBlindWrite = options.useMultiplexedSessionBlindWrite;
       this.useMultiplexedSessionForRW = options.useMultiplexedSessionForRW;
       this.useMultiplexedSessionPartitionedOps = options.useMultiplexedSessionForPartitionedOps;
       this.multiplexedSessionMaintenanceDuration = options.multiplexedSessionMaintenanceDuration;
@@ -857,17 +845,6 @@ Builder setUseMultiplexedSession(boolean useMultiplexedSession) {
       return this;
     }
 
-    /**
-     * This method enables multiplexed sessions for blind writes. This method will be removed in the
-     * future when multiplexed sessions has been made the default for all operations.
-     */
-    @InternalApi
-    @VisibleForTesting
-    Builder setUseMultiplexedSessionBlindWrite(boolean useMultiplexedSessionBlindWrite) {
-      this.useMultiplexedSessionBlindWrite = useMultiplexedSessionBlindWrite;
-      return this;
-    }
-
     /**
      * Sets whether the client should use multiplexed session for R/W operations or not. This method
      * is intentionally package-private and intended for internal use.

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

@@ -93,7 +93,6 @@ public void createSpannerInstance() {
             .setSessionPoolOption(
                 SessionPoolOptions.newBuilder()
                     .setUseMultiplexedSession(true)
-                    .setUseMultiplexedSessionBlindWrite(true)
                     .setUseMultiplexedSessionForRW(true)
                     .setUseMultiplexedSessionPartitionedOps(true)
                     // Set the maintainer to loop once every 1ms

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

@@ -1288,6 +1288,9 @@ public void write() throws InterruptedException {
 
   @Test
   public void writeAtLeastOnce() throws InterruptedException {
+    assumeFalse(
+        "Multiplexed session do not throw a SessionNotFound errors. ",
+        spanner.getOptions().getSessionPoolOptions().getUseMultiplexedSession());
     assertThrowsSessionNotFoundIfShouldFail(
         () ->
             client.writeAtLeastOnce(