more batching to improve checkkeys latency, new memory usage metrics (#987)

* more aggressive command batching to reduce roundtrips and improve scrape duration when exporter-to-instance latency is high.

* update README, add that checkKeys doesn't work in cluster mode because SCAN does not work across multiple instances

Author: oliver006

.github/workflows/tests.yml

@@ -49,7 +49,6 @@ jobs:
           LOG_LEVEL: "info"
         run: |
           sleep 15
-          make checks
           make test
 
 
@@ -102,6 +101,12 @@ jobs:
           version: v1.64
           args: "--tests=false"
 
+      - name: Run checks
+        env:
+          LOG_LEVEL: "info"
+        run: |
+          make checks
+
 
   build-stuff:
     runs-on: ubuntu-latest

README.md

@@ -89,15 +89,11 @@ services:
 
   redis-cluster:
     image: grokzen/redis-cluster:6.2.14
+    environment:
+      - IP=0.0.0.0
     ports:
-      - "7000"
-      - "7001"
-      - "7002"
-      - "7003"
-      - "7004"
-      - "7005"
-      - "17000:7000"
-      - "17005:7005"
+      - 7000-7005:7000-7005
+      - 17000-17005:7000-7005
 
   redis-cluster-password:
     image: bitnami/redis-cluster:7.4

docker-compose.yml

@@ -27,7 +27,6 @@ type Exporter struct {
 	sync.Mutex
 
 	redisAddr string
-	namespace string
 
 	totalScrapes              prometheus.Counter
 	scrapeDuration            prometheus.Summary
@@ -103,7 +102,6 @@ func NewRedisExporter(uri string, opts Options) (*Exporter, error) {
 	e := &Exporter{
 		redisAddr: uri,
 		options:   opts,
-		namespace: opts.Namespace,
 
 		buildInfo: opts.BuildInfo,
 
@@ -433,6 +431,7 @@ func NewRedisExporter(uri string, opts Options) (*Exporter, error) {
 		"key_size":                                           {txt: `The length or size of "key"`, lbls: []string{"db", "key"}},
 		"key_value":                                          {txt: `The value of "key"`, lbls: []string{"db", "key"}},
 		"key_value_as_string":                                {txt: `The value of "key" as a string`, lbls: []string{"db", "key", "val"}},
+		"key_memory_usage_bytes":                             {txt: `The memory usage of "key" in bytes`, lbls: []string{"db", "key"}},
 		"keys_count":                                         {txt: `Count of keys`, lbls: []string{"db", "key"}},
 		"last_key_groups_scrape_duration_milliseconds":       {txt: `Duration of the last key group metrics scrape in milliseconds`},
 		"last_slow_execution_duration_seconds":               {txt: `The amount of time needed for last slow execution, in seconds`},