[receiver/redis] Add missing metric units (#23573)

**Description:**

Metric unit is required, see:
https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/cmd/mdatagen/metadata-schema.yaml#L72-L73.

This PR adds the unit to metrics where this is missing:
- redis.role
- redis.cmd.calls
- redis.clients.connected
- redis.clients.blocked
- redis.keys.expired
- redis.keys.evicted
- redis.connections.received
- redis.connections.rejected
- redis.memory.fragmentation_ratio
- redis.rdb.changes_since_last_save
- redis.commands.processed
- redis.keyspace.hits
- redis.keyspace.misses
- redis.slaves.connected
- redis.db.keys
- redis.db.expires

.chloggen/add-units-to-redisreceiver.yaml

@@ -0,0 +1,38 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: redisreceiver
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Adds unit to metrics where this was missing.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [23573]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: |
+ Affected metrics can be found below.
+ - redis.role
+ - redis.cmd.calls
+ - redis.clients.connected
+ - redis.clients.blocked
+ - redis.keys.expired
+ - redis.keys.evicted
+ - redis.connections.received
+ - redis.connections.rejected
+ - redis.memory.fragmentation_ratio
+ - redis.rdb.changes_since_last_save
+ - redis.commands.processed
+ - redis.keyspace.hits
+ - redis.keyspace.misses
+ - redis.slaves.connected
+ - redis.db.keys
+ - redis.db.expires
+

receiver/redisreceiver/documentation.md

@@ -18,15 +18,15 @@ Number of clients pending on a blocking call
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | false |
+| {client} | Sum | Int | Cumulative | false |
 
 ### redis.clients.connected
 
 Number of client connections (excluding connections from replicas)
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | false |
+| {client} | Sum | Int | Cumulative | false |
 
 ### redis.clients.max_input_buffer
 
@@ -58,23 +58,23 @@ Total number of commands processed by the server
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | true |
+| {command} | Sum | Int | Cumulative | true |
 
 ### redis.connections.received
 
 Total number of connections accepted by the server
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | true |
+| {connection} | Sum | Int | Cumulative | true |
 
 ### redis.connections.rejected
 
 Number of connections rejected because of maxclients limit
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | true |
+| {connection} | Sum | Int | Cumulative | true |
 
 ### redis.cpu.time
 
@@ -110,7 +110,7 @@ Number of keyspace keys with an expiration
 
 | Unit | Metric Type | Value Type |
 | ---- | ----------- | ---------- |
-| | Gauge | Int |
+| {key} | Gauge | Int |
 
 #### Attributes
 
@@ -124,7 +124,7 @@ Number of keyspace keys
 
 | Unit | Metric Type | Value Type |
 | ---- | ----------- | ---------- |
-| | Gauge | Int |
+| {key} | Gauge | Int |
 
 #### Attributes
 
@@ -138,31 +138,31 @@ Number of evicted keys due to maxmemory limit
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | true |
+| {key} | Sum | Int | Cumulative | true |
 
 ### redis.keys.expired
 
 Total number of key expiration events
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | true |
+| {event} | Sum | Int | Cumulative | true |
 
 ### redis.keyspace.hits
 
 Number of successful lookup of keys in the main dictionary
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | true |
+| {hit} | Sum | Int | Cumulative | true |
 
 ### redis.keyspace.misses
 
 Number of failed lookup of keys in the main dictionary
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | true |
+| {miss} | Sum | Int | Cumulative | true |
 
 ### redis.latest_fork
 
@@ -178,7 +178,7 @@ Ratio between used_memory_rss and used_memory
 
 | Unit | Metric Type | Value Type |
 | ---- | ----------- | ---------- |
-| | Gauge | Double |
+| 1 | Gauge | Double |
 
 ### redis.memory.lua
 
@@ -234,7 +234,7 @@ Number of changes since the last dump
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | false |
+| {change} | Sum | Int | Cumulative | false |
 
 ### redis.replication.backlog_first_byte_offset
 
@@ -258,7 +258,7 @@ Number of connected replicas
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | false |
+| {replica} | Sum | Int | Cumulative | false |
 
 ### redis.uptime
 
@@ -284,7 +284,7 @@ Total number of calls for a command
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | true |
+| {call} | Sum | Int | Cumulative | true |
 
 #### Attributes
 
@@ -320,7 +320,7 @@ Redis node's role
 
 | Unit | Metric Type | Value Type | Aggregation Temporality | Monotonic |
 | ---- | ----------- | ---------- | ----------------------- | --------- |
-| | Sum | Int | Cumulative | false |
+| {role} | Sum | Int | Cumulative | false |
 
 #### Attributes