chore: Add spanner configuration in logs, Update Metrics documentation (#2455)

* chore: Add spanner configuration in logs, Update Metrics documentation

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: surbhigarg92

.readme-partials.yml

@@ -4,6 +4,28 @@ introduction: |-
         and automatic, synchronous replication for high availability.
 
 body: |-
+        ## Metrics
+        
+        Cloud Spanner client supports [client-side metrics](https://cloud.google.com/spanner/docs/view-manage-client-side-metrics) that you can use along with server-side metrics to optimize performance and troubleshoot performance issues if they occur.
+        
+        Client-side metrics are measured from the time a request leaves your application to the time your application receives the response. 
+        In contrast, server-side metrics are measured from the time Spanner receives a request until the last byte of data is sent to the client.
+        
+        These metrics are enabled by default. You can opt out of using client-side metrics with the following code:
+        
+        ```javascript
+        const spanner = new Spanner({
+                disableBuiltInMetrics: true
+        });
+        ```
+        
+        You can also disable these metrics by setting `SPANNER_DISABLE_BUILTIN_METRICS` to `true`.
+        
+        > Note: Client-side metrics needs `monitoring.timeSeries.create` IAM permission to export metrics data. Ask your administrator to grant your service account the [Monitoring Metric Writer](https://cloud.google.com/iam/docs/roles-permissions/monitoring#monitoring.metricWriter) (roles/monitoring.metricWriter) IAM role on the project.
+
+        ## Traces
+        Refer to the Observability README to know more about tracing support in the Cloud Spanner client.
+
         ## Multiplexed Sessions
 
         Spanner's Multiplexed Sessions can now be used as an efficient alternative to the default session pool. This feature helps reduce

README.md

@@ -80,6 +80,28 @@ console.log(`Query: ${rows.length} found.`);
 rows.forEach(row => console.log(row));
 
 ```
+## Metrics
+
+Cloud Spanner client supports [client-side metrics](https://cloud.google.com/spanner/docs/view-manage-client-side-metrics) that you can use along with server-side metrics to optimize performance and troubleshoot performance issues if they occur.
+
+Client-side metrics are measured from the time a request leaves your application to the time your application receives the response. 
+In contrast, server-side metrics are measured from the time Spanner receives a request until the last byte of data is sent to the client.
+
+These metrics are enabled by default. You can opt out of using client-side metrics with the following code:
+
+```javascript
+const spanner = new Spanner({
+        disableBuiltInMetrics: true
+});
+```
+
+You can also disable these metrics by setting `SPANNER_DISABLE_BUILTIN_METRICS` to `true`.
+
+> Note: Client-side metrics needs `monitoring.timeSeries.create` IAM permission to export metrics data. Ask your administrator to grant your service account the [Monitoring Metric Writer](https://cloud.google.com/iam/docs/roles-permissions/monitoring#monitoring.metricWriter) (roles/monitoring.metricWriter) IAM role on the project.
+
+## Traces
+Refer to the Observability README to know more about tracing support in the Cloud Spanner client.
+
 ## Multiplexed Sessions
 
 Spanner's Multiplexed Sessions can now be used as an efficient alternative to the default session pool. This feature helps reduce

src/index.ts

@@ -502,6 +502,7 @@ class Spanner extends GrpcService {
     this._universeDomain = universeEndpoint;
     this.projectId_ = options.projectId;
     this.configureMetrics_(options.disableBuiltInMetrics);
+    this._logSpannerConfigurations(config);
   }
 
   get universeDomain() {
@@ -1662,6 +1663,33 @@ class Spanner extends GrpcService {
     }
   }
 
+  /**
+   * Logs the Spanner configurations that have been set.
+   *
+   * @private
+   */
+  private _logSpannerConfigurations(config: GrpcServiceConfig): void {
+    try {
+      const afeServerTiming = Spanner.isAFEServerTimingEnabled();
+      console.log(
+        'Spanner configurations:\n' +
+          `  Project ID: ${this.projectId_}\n` +
+          `  Spanner Emulator Host: ${process.env.SPANNER_EMULATOR_HOST || 'not set'}\n` +
+          `  Base URL: ${config.baseUrl}\n` +
+          `  Leader aware routing enabled: ${this.routeToLeaderEnabled}\n` +
+          `  Built in metrics enabled: ${MetricsTracerFactory.enabled}\n` +
+          `  AFE Server Timing enabled: ${afeServerTiming}\n` +
+          `  Spanner extended tracing enabled: ${this._observabilityOptions?.enableExtendedTracing === true || process.env.SPANNER_ENABLE_EXTENDED_TRACING === 'true' || false}\n` +
+          `  Spanner end-to-end tracing enabled: ${this._observabilityOptions?.enableEndToEndTracing === true || process.env.SPANNER_ENABLE_END_TO_END_TRACING === 'true' || false}\n` +
+          `  GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS: ${process.env.GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS || 'not set'}\n` +
+          `  GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS_PARTITIONED_OPS: ${process.env.GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS_PARTITIONED_OPS || 'not set'}\n` +
+          `  GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS_FOR_RW: ${process.env.GOOGLE_CLOUD_SPANNER_MULTIPLEXED_SESSIONS_FOR_RW || 'not set'}\n  `,
+      );
+    } catch (error) {
+      console.log('Unable to log Spanner configurations:\n' + error);
+    }
+  }
+
   /**
    * Prepare a gapic request. This will cache the GAX client and replace
    * {{projectId}} placeholders, if necessary.