Add WebSocket failover counter metric and URL change logging (#661)

* Add WebSocket failover counter metric, abnormal closure tracking, and URL change logging

* Remove increment on 1006

* Remove bad description

* run prettier

Author: cawthorne

src/metrics/index.ts

@@ -357,4 +357,9 @@ export const metrics = new Metrics(() => ({
     help: 'The number of addresses in PoR request input parameters',
     labelNames: ['feed_id'] as const,
   }),
+  wsConnectionFailoverCount: new client.Gauge({
+    name: 'ws_connection_failover_count',
+    help: 'The number of consecutive unresponsive connection detections (no data for WS_SUBSCRIPTION_UNRESPONSIVE_TTL), used to trigger URL failover',
+    labelNames: ['transport_name'] as const,
+  }),
 }))

src/transports/websocket.ts

@@ -414,9 +414,13 @@ export class WebSocketTransport<
     // to determine minimum TTL of an open connection given no explicit connection errors.
     if (connectionUnresponsive) {
       this.streamHandlerInvocationsWithNoConnection += 1
-      logger.trace(
-        `The connection is unresponsive, incremented streamHandlerIterationsWithNoConnection = ${this.streamHandlerInvocationsWithNoConnection}`,
+      logger.info(
+        `The connection is unresponsive (last message ${timeSinceLastMessage}ms ago), incremented failover counter to ${this.streamHandlerInvocationsWithNoConnection}`,
       )
+      metrics
+        .get('wsConnectionFailoverCount')
+        .labels({ transport_name: this.name })
+        .set(this.streamHandlerInvocationsWithNoConnection)
     }
 
     // We want to check if the URL we calculate is different from the one currently connected.
@@ -431,10 +435,9 @@ export class WebSocketTransport<
     // Check if we should close the current connection
     if (!connectionClosed && (urlChanged || connectionUnresponsive)) {
       if (urlChanged) {
+        logger.info('Websocket URL has changed, closing connection to reconnect...')
         censorLogs(() =>
-          logger.debug(
-            `Websocket url has changed from ${this.currentUrl} to ${urlFromConfig}, closing connection...`,
-          ),
+          logger.debug(`Websocket URL changed from ${this.currentUrl} to ${urlFromConfig}`),
         )
       } else {
         censorLogs(() =>