chore: Logs for Spanner Options

Author: surbhigarg92

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

@@ -141,6 +141,7 @@ static final class ClosedException extends RuntimeException {
   @VisibleForTesting
   SpannerImpl(SpannerRpc gapicRpc, SpannerOptions options) {
     super(options);
+    logger.log(Level.CONFIG, "Creating Spanner instance");
     this.gapicRpc = gapicRpc;
     this.asyncExecutorProvider =
         MoreObjects.firstNonNull(
@@ -149,12 +150,53 @@ static final class ClosedException extends RuntimeException {
     this.dbAdminClient = new DatabaseAdminClientImpl(options.getProjectId(), gapicRpc);
     this.instanceClient =
         new InstanceAdminClientImpl(options.getProjectId(), gapicRpc, dbAdminClient);
+    logSpannerOptions(options);
   }
 
   SpannerImpl(SpannerOptions options) {
     this(options.getSpannerRpcV1(), options);
   }
 
+  private void logSpannerOptions(SpannerOptions options) {
+    if (logger.isLoggable(Level.CONFIG)) {
+      logger.log(
+          Level.CONFIG,
+          "Spanner options: "
+              + "\nProject ID: "
+              + options.getProjectId()
+              + "\nHost: "
+              + options.getHost()
+              + "\nNum gRPC channels: "
+              + options.getNumChannels()
+              + "\nLeader aware routing enabled: "
+              + options.isLeaderAwareRoutingEnabled()
+              + "\nDirect access enabled: "
+              + options.isEnableDirectAccess()
+              + "\nActive Tracing Framework: "
+              + SpannerOptions.getActiveTracingFramework()
+              + "\nAPI tracing enabled: "
+              + options.isEnableApiTracing()
+              + "\nExtended tracing enabled: "
+              + options.isEnableExtendedTracing()
+              + "\nEnd to end tracing enabled: "
+              + options.isEndToEndTracingEnabled()
+              + "\nBuilt-in metrics enabled: "
+              + options.isEnableBuiltInMetrics()
+              + "\nSession pool min sessions: "
+              + options.getSessionPoolOptions().getMinSessions()
+              + "\nSession pool max sessions: "
+              + options.getSessionPoolOptions().getMaxSessions()
+              + "\nMultiplexed sessions enabled: "
+              + options.getSessionPoolOptions().getUseMultiplexedSession()
+              + "\nMultiplexed sessions enabled for RW: "
+              + options.getSessionPoolOptions().getUseMultiplexedSessionForRW()
+              + "\nMultiplexed sessions enabled for blind write: "
+              + options.getSessionPoolOptions().getUseMultiplexedSessionBlindWrite()
+              + "\nMultiplexed sessions enabled for partitioned ops: "
+              + options.getSessionPoolOptions().getUseMultiplexedSessionPartitionedOps());
+    }
+  }
+
   /** Returns the {@link SpannerRpc} of this {@link SpannerImpl} instance. */
   SpannerRpc getRpc() {
     return gapicRpc;