Add hookshot_ prefix on hookshot specific metrics (#701)

* Add hookshot_ prefix on all metrics

* Only add prefix to hookshot specific metrics

* Add old metric names as deprecated

* Fix feeds metrics names

* Update metrics docs

---------

Co-authored-by: Will Hunt <will@half-shot.uk>

changelog.d/701.misc

@@ -0,0 +1 @@
+Ensure all Hookshot specific metrics have a `hookshot_` prefix.

contrib/hookshot-dashboard.json

@@ -1369,7 +1369,7 @@
             },
             "editorMode": "builder",
             "exemplar": false,
-            "expr": "feed_count",
+            "expr": "hookshot_feeds_count",
             "instant": false,
             "legendFormat": "{{__name__}}",
             "range": true,
@@ -1462,7 +1462,7 @@
               "uid": "${datasource}"
             },
             "editorMode": "builder",
-            "expr": "feed_fetch_ms",
+            "expr": "hookshot_feeds_fetch_ms",
             "legendFormat": "{{__name__}}",
             "range": true,
             "refId": "A"

docs/metrics.md

@@ -31,6 +31,9 @@ Below is the generated list of Prometheus metrics for Hookshot.
 | hookshot_notifications_push | Number of notifications pushed | service |
 | hookshot_notifications_service_up | Is the notification service up or down | service |
 | hookshot_notifications_watchers | Number of notifications watchers running | service |
+| hookshot_feeds_count | The number of RSS feeds that hookshot is subscribed to |  |
+| hookshot_feeds_fetch_ms | The time taken for hookshot to fetch all feeds |  |
+| hookshot_feeds_failing | The number of RSS feeds that hookshot is failing to read | reason |
 ## matrix
 | Metric | Help | Labels |
 |--------|------|--------|
@@ -41,9 +44,9 @@ Below is the generated list of Prometheus metrics for Hookshot.
 ## feed
 | Metric | Help | Labels |
 |--------|------|--------|
-| feed_count | The number of RSS feeds that hookshot is subscribed to |  |
+| feed_count | (Deprecated) The number of RSS feeds that hookshot is subscribed to |  |
-| feed_fetch_ms | The time taken for hookshot to fetch all feeds |  |
+| feed_fetch_ms | (Deprecated) The time taken for hookshot to fetch all feeds |  |
-| feed_failing | The number of RSS feeds that hookshot is failing to read | reason |
+| feed_failing | (Deprecated) The number of RSS feeds that hookshot is failing to read | reason |
 ## process
 | Metric | Help | Labels |
 |--------|------|--------|

src/Metrics.ts

@@ -24,15 +24,18 @@ export class Metrics {
     public readonly matrixAppserviceEvents = new Counter({ name: "matrix_appservice_events", help: "The number of events sent over the AS API", labelNames: [], registers: [this.registry]});
     public readonly matrixAppserviceDecryptionFailed = new Counter({ name: "matrix_appservice_decryption_failed", help: "The number of events sent over the AS API that failed to decrypt", registers: [this.registry]});
 
-    public readonly feedsCount = new Gauge({ name: "feed_count", help: "The number of RSS feeds that hookshot is subscribed to", labelNames: [], registers: [this.registry]});
+    public readonly feedsCount = new Gauge({ name: "hookshot_feeds_count", help: "The number of RSS feeds that hookshot is subscribed to", labelNames: [], registers: [this.registry]});
-    public readonly feedFetchMs = new Gauge({ name: "feed_fetch_ms", help: "The time taken for hookshot to fetch all feeds", labelNames: [], registers: [this.registry]});
+    public readonly feedFetchMs = new Gauge({ name: "hookshot_feeds_fetch_ms", help: "The time taken for hookshot to fetch all feeds", labelNames: [], registers: [this.registry]});
-    public readonly feedsFailing = new Gauge({ name: "feed_failing", help: "The number of RSS feeds that hookshot is failing to read", labelNames: ["reason"], registers: [this.registry]});
+    public readonly feedsFailing = new Gauge({ name: "hookshot_feeds_failing", help: "The number of RSS feeds that hookshot is failing to read", labelNames: ["reason"], registers: [this.registry]});
+    public readonly feedsCountDeprecated = new Gauge({ name: "feed_count", help: "(Deprecated) The number of RSS feeds that hookshot is subscribed to", labelNames: [], registers: [this.registry]});
+    public readonly feedsFetchMsDeprecated = new Gauge({ name: "feed_fetch_ms", help: "(Deprecated) The time taken for hookshot to fetch all feeds", labelNames: [], registers: [this.registry]});
+    public readonly feedsFailingDeprecated = new Gauge({ name: "feed_failing", help: "(Deprecated) The number of RSS feeds that hookshot is failing to read", labelNames: ["reason"], registers: [this.registry]});
 
 
     constructor(private registry: Registry = register) {
         this.expressRouter.get('/metrics', this.metricsFunc.bind(this));
         collectDefaultMetrics({
-            register: this.registry
+            register: this.registry,
         })
     }
 

src/feeds/FeedReader.ts

@@ -170,7 +170,7 @@ export class FeedReader {
     private seenEntries: Map<string, string[]> = new Map();
     // A set of last modified times for each url.
     private cacheTimes: Map<string, { etag?: string, lastModified?: string}> = new Map();
-    
+
     // Reason failures to url map.
     private feedsFailingHttp = new Set();
     private feedsFailingParsing = new Set();
@@ -232,6 +232,7 @@ export class FeedReader {
         this.feedQueue = shuffle([...this.observedFeedUrls.values()]);
 
         Metrics.feedsCount.set(this.observedFeedUrls.size);
+        Metrics.feedsCountDeprecated.set(this.observedFeedUrls.size);
     }
 
     private async loadSeenEntries(): Promise<void> {
@@ -268,7 +269,7 @@ export class FeedReader {
      * Poll a given feed URL for data, pushing any entries found into the message queue.
      * We also check the `cacheTimes` cache to see if the feed has recent entries that we can
      * filter out.
-     * 
+     *
      * @param url The URL to be polled.
      * @returns A boolean that returns if we saw any changes on the feed since the last poll time.
      */
@@ -288,7 +289,7 @@ export class FeedReader {
                 this.config.pollTimeoutSeconds * 1000,
                 this.parser,
             );
-            
+
             // Store any entity tags/cache times.
             if (response.headers.ETag) {
                 this.cacheTimes.set(url, { etag: response.headers.ETag});
@@ -354,7 +355,7 @@ export class FeedReader {
                 // Some RSS feeds can return a very small number of items then bounce
                 // back to their "normal" size, so we cannot just clobber the recent GUID list per request or else we'll
                 // forget what we sent and resend it. Instead, we'll keep 2x the max number of items that we've ever
-                // seen from this feed, up to a max of 10,000. 
+                // seen from this feed, up to a max of 10,000.
                 // Adopted from https://github.com/matrix-org/go-neb/blob/babb74fa729882d7265ff507b09080e732d060ae/services/rssbot/rssbot.go#L304
                 const maxGuids = Math.min(Math.max(2 * newGuids.length, seenGuids.length), 10_000);
                 const newSeenItems = Array.from(new Set([ ...newGuids, ...seenGuids ]).values()).slice(0, maxGuids);
@@ -399,9 +400,12 @@ export class FeedReader {
 
         Metrics.feedsFailing.set({ reason: "http" }, this.feedsFailingHttp.size );
         Metrics.feedsFailing.set({ reason: "parsing" }, this.feedsFailingParsing.size);
+        Metrics.feedsFailingDeprecated.set({ reason: "http" }, this.feedsFailingHttp.size );
+        Metrics.feedsFailingDeprecated.set({ reason: "parsing" }, this.feedsFailingParsing.size);
 
         const elapsed = Date.now() - fetchingStarted;
         Metrics.feedFetchMs.set(elapsed);
+        Metrics.feedsFetchMsDeprecated.set(elapsed);
 
         const sleepFor = Math.max(this.sleepingInterval - elapsed, 0);
         log.debug(`Feed fetching took ${elapsed / 1000}s, sleeping for ${sleepFor / 1000}s`);