[misc] EventLogger: drop explicit metrics.inc amount

The module has a hard-coded increment of 1, which is the only value the
 prometheus backend supports.

services/real-time/app/js/EventLogger.js

@@ -43,7 +43,7 @@ module.exports = EventLogger = {
     // store the last count in a hash for each host
     const previous = EventLogger._storeEventCount(key, count)
     if (!previous || count === previous + 1) {
-      metrics.inc(`event.${channel}.valid`, 0.001) // downsample high rate docupdater events
+      metrics.inc(`event.${channel}.valid`)
       return // order is ok
     }
     if (count === previous) {

services/real-time/test/unit/js/EventLoggerTests.js

@@ -55,7 +55,7 @@ describe('EventLogger', function () {
 
       return it('should increment the valid event metric', function () {
         return this.metrics.inc
-          .calledWith(`event.${this.channel}.valid`, 1)
+          .calledWith(`event.${this.channel}.valid`)
           .should.equals(true)
       })
     })
@@ -80,7 +80,7 @@ describe('EventLogger', function () {
 
       return it('should increment the duplicate event metric', function () {
         return this.metrics.inc
-          .calledWith(`event.${this.channel}.duplicate`, 1)
+          .calledWith(`event.${this.channel}.duplicate`)
           .should.equals(true)
       })
     })
@@ -110,7 +110,7 @@ describe('EventLogger', function () {
 
       return it('should increment the out-of-order event metric', function () {
         return this.metrics.inc
-          .calledWith(`event.${this.channel}.out-of-order`, 1)
+          .calledWith(`event.${this.channel}.out-of-order`)
           .should.equals(true)
       })
     })