fix(grpc): clean up disconnected streams

services/grpc/grpcService.js

@@ -145,32 +145,42 @@ class GrpcService extends EventEmitter {
    */
   subscribe() {
     // this.subscriptions['something'] = this.service.subscribeToSomething()
+    // super.subscribe()
+
+    // Close and clear subscriptions when they emit an end event.
+    const activeSubKeys = Object.keys(this.subscriptions)
+    activeSubKeys.forEach(key => {
+      const call = this.subscriptions[key]
+      call.on('end', () => {
+        grpcLog.info(`gRPC subscription "${this.serviceName}.${key}" ended.`)
+        delete this.subscriptions[key]
+      })
+    })
   }
 
   /**
    * Unsubscribe from all streams.
    */
   async unsubscribe() {
     const activeSubKeys = Object.keys(this.subscriptions)
-    if (activeSubKeys.length) {
-      grpcLog.info(`Unsubscribing from all ${this.serviceName} gRPC streams: %o`, activeSubKeys)
-      const cancellations = activeSubKeys.map(key => this._cancelSubscription(key))
-      return Promise.all(cancellations)
-    }
+    grpcLog.info(`Unsubscribing from all ${this.serviceName} gRPC streams: %o`, activeSubKeys)
+    const cancellations = activeSubKeys.map(key => this._cancelSubscription(key))
+    await Promise.all(cancellations)
   }
 
   /**
    * Unsubscribe from a single stream.
    */
   async _cancelSubscription(key) {
-    grpcLog.info(`Unsubscribing from ${key} gRPC stream`)
+    grpcLog.info(`Unsubscribing from ${this.serviceName}.${key} gRPC stream`)
     const call = this.subscriptions[key]
 
     // Cancellation status callback handler.
     const result = new Promise(resolve => {
       call.on('status', callStatus => {
         if (callStatus.code === status.CANCELLED) {
-          grpcLog.info(`Unsubscribed from ${key} gRPC stream`)
+          delete this.subscriptions[key]
+          grpcLog.info(`Unsubscribed from ${this.serviceName}.${key} gRPC stream`)
           resolve()
         }
       })

services/grpc/lightning/lightning.js

@@ -61,6 +61,7 @@ class Lightning extends LndGrpcService {
     this.subscriptions['channelGraph'] = this.subscribeChannelGraph()
     this.subscriptions['invoices'] = this.subscribeInvoices()
     this.subscriptions['transactions'] = this.subscribeTransactions()
+    super.subscribe()
   }
 }