Fields renamed on redis 5.0 (#8167) (#8202)

Some fields are renamed on future redis 5.0, use the new terminology on
these fields and deprecate the old ones. While old fields are not
removed, both are filled with the same value.

Tests executed also on redis 4 and 5.

(cherry picked from commit b5f225f)

CHANGELOG.asciidoc

@@ -91,6 +91,7 @@ https://github.com/elastic/beats/compare/v6.4.0...6.x[Check the HEAD diff]
 - Move common kafka fields (broker, topic and partition.id) to the module level to facilitate events correlation {pull}7767[7767]
 - Add fields for memory fragmentation, memory allocator stats, copy on write, master-slave status, and active defragmentation to `info` metricset of Redis module. {pull}7695[7695]
 - Increase ignore_above for system.process.cmdline to 2048. {pull}8101[8100]
+- Add support to renamed fields planned for redis 5.0. {pull}8167[8167]
 
 
 - Add `metrics` metricset to MongoDB module. {pull}7611[7611]
@@ -110,6 +111,7 @@ https://github.com/elastic/beats/compare/v6.4.0...6.x[Check the HEAD diff]
 
 *Metricbeat*
 - Redis `info` `replication.master_offset` has been deprecated in favor of `replication.master.offset`.{pull}7695[7695]
+- Redis `info` clients fields `longest_output_list` and `biggest_input_buf` have been renamed to `max_output_buffer` and `max_input_buffer` based on the names they will have in Redis 5.0, both fields will coexist during a time with the same value {pull}8167[8167].
 
 - Move common kafka fields (broker, topic and partition.id) to the module level {pull}7767[7767].
 

metricbeat/docker-compose.yml

@@ -160,6 +160,18 @@ services:
   redis:
     build: ./module/redis/_meta
 
+  redis_4:
+    build:
+      context: ./module/redis/_meta
+      args:
+        REDIS_VERSION: 4.0.11
+
+  redis_5:
+    build:
+      context: ./module/redis/_meta
+      args:
+        REDIS_VERSION: 5.0-rc4
+
   traefik:
     build: ./module/traefik/_meta
 

metricbeat/docs/fields.asciidoc

@@ -16083,6 +16083,19 @@ Number of client connections (excluding connections from slaves).
 *`redis.info.clients.longest_output_list`*::
 +
 --
+
+deprecated[6.5.0]
+
+type: long
+
+Longest output list among current client connections (replaced by max_output_buffer).
+
+
+--
+
+*`redis.info.clients.max_output_buffer`*::
++
+--
 type: long
 
 Longest output list among current client connections.
@@ -16093,9 +16106,22 @@ Longest output list among current client connections.
 *`redis.info.clients.biggest_input_buf`*::
 +
 --
+
+deprecated[6.5.0]
+
+type: long
+
+Biggest input buffer among current client connections (replaced by max_input_buffer).
+
+
+--
+
+*`redis.info.clients.max_input_buffer`*::
++
+--
 type: long
 
-Biggest input buffer among current client connections.
+Biggest input buffer among current client connections (on redis 5.0).
 
 
 --

metricbeat/docs/modules/redis.asciidoc

@@ -29,8 +29,8 @@ The Redis module has these additional config options:
 [float]
 === Compatibility
 
-The Redis metricsets were tested with Redis 3.2.4 and are expected to work with all version
->= 3.0.
+The Redis metricsets were tested with Redis 3.2.12, 4.0.11 and 5.0-rc4,  and are expected
+to work with all versions >= 3.0.
 
 
 [float]

metricbeat/module/redis/_meta/Dockerfile

@@ -1,2 +1,3 @@
-FROM redis:3.2.4-alpine
+ARG REDIS_VERSION=3.2.12
+FROM redis:${REDIS_VERSION}-alpine
 HEALTHCHECK --interval=1s --retries=90 CMD nc -z localhost 6379

metricbeat/module/redis/_meta/docs.asciidoc

@@ -22,5 +22,5 @@ The Redis module has these additional config options:
 [float]
 === Compatibility
 
-The Redis metricsets were tested with Redis 3.2.4 and are expected to work with all version
->= 3.0.
+The Redis metricsets were tested with Redis 3.2.12, 4.0.11 and 5.0-rc4,  and are expected
+to work with all versions >= 3.0.

metricbeat/module/redis/info/_meta/data.json

@@ -16,7 +16,9 @@
                 "biggest_input_buf": 0,
                 "blocked": 0,
                 "connected": 1,
-                "longest_output_list": 0
+                "longest_output_list": 0,
+                "max_input_buffer": 0,
+                "max_output_buffer": 0
             },
             "cluster": {
                 "enabled": false

metricbeat/module/redis/info/_meta/fields.yml

@@ -14,13 +14,23 @@
           description: >
             Number of client connections (excluding connections from slaves).
         - name: longest_output_list
+          type: long
+          deprecated: "6.5.0"
+          description: >
+            Longest output list among current client connections (replaced by max_output_buffer).
+        - name: max_output_buffer
           type: long
           description: >
             Longest output list among current client connections.
         - name: biggest_input_buf
+          type: long
+          deprecated: "6.5.0"
+          description: >
+            Biggest input buffer among current client connections (replaced by max_input_buffer).
+        - name: max_input_buffer
           type: long
           description: >
-            Biggest input buffer among current client connections.
+            Biggest input buffer among current client connections (on redis 5.0).
         - name: blocked
           type: long
           description: >

metricbeat/module/redis/info/data.go

@@ -29,6 +29,8 @@ var (
 			"connected":           c.Int("connected_clients"),
 			"longest_output_list": c.Int("client_longest_output_list"),
 			"biggest_input_buf":   c.Int("client_biggest_input_buf"),
+			"max_output_buffer":   c.Int("client_recent_max_output_buffer"),
+			"max_input_buffer":    c.Int("client_recent_max_input_buffer"),
 			"blocked":             c.Int("blocked_clients"),
 		},
 		"cluster": s.Object{

metricbeat/module/redis/info/info.go

@@ -80,6 +80,21 @@ func (m *MetricSet) Fetch() (common.MapStr, error) {
 		return nil, err
 	}
 
+	// In 5.0 some fields are renamed, maintain both names, old ones will be deprecated
+	renamings := []struct {
+		old, new string
+	}{
+		{"client_longest_output_list", "client_recent_max_output_buffer"},
+		{"client_biggest_input_buf", "client_recent_max_input_buffer"},
+	}
+	for _, r := range renamings {
+		if v, ok := info[r.new]; ok {
+			info[r.old] = v
+		} else {
+			info[r.new] = info[r.old]
+		}
+	}
+
 	slowLogLength, err := redis.FetchSlowLogLength(m.pool.Get())
 	if err != nil {
 		return nil, err

metricbeat/tests/system/test_redis.py

@@ -15,7 +15,8 @@
               "used.user_children"]
 
 CLIENTS_FIELDS = ["blocked", "biggest_input_buf",
-                  "longest_output_list", "connected"]
+                  "longest_output_list", "connected",
+                  "max_input_buffer", "max_output_buffer"]
 
 
 class Test(metricbeat.BaseTest):
@@ -58,7 +59,10 @@ def test_keyspace(self):
         """
 
         # At least one event must be inserted so db stats exist
-        r = redis.StrictRedis(host=os.getenv('REDIS_HOST', 'localhost'), port=os.getenv('REDIS_PORT', '6379'), db=0)
+        r = redis.StrictRedis(
+            host=self.compose_hosts()[0],
+            port=os.getenv('REDIS_PORT', '6379'),
+            db=0)
         r.set('foo', 'bar')
 
         self.render_config_template(modules=[{
@@ -116,5 +120,13 @@ def test_module_processors(self):
         self.assertItemsEqual(self.de_dot(CPU_FIELDS), redis_info["cpu"].keys())
 
     def get_hosts(self):
-        return [os.getenv('REDIS_HOST', 'localhost') + ':' +
+        return [self.compose_hosts()[0] + ':' +
                 os.getenv('REDIS_PORT', '6379')]
+
+
+class TestRedis4(Test):
+    COMPOSE_SERVICES = ['redis_4']
+
+
+class TestRedis5(Test):
+    COMPOSE_SERVICES = ['redis_5']