feat(redis): Allow configuring Redis pools individually (#3859)

Second attempt at #3843.
Implements #3829.

This time around, if there is only one Redis pool configuration, we only
create one pool and clone it 4 ways (instead of creating 4 identical
pools like last time). This means that the case of only one
configuration preserves the current behavior, modulo the bug fix related
to `DEFAULT_MIN_MAX_CONNECTIONS`.

CHANGELOG.md

@@ -21,6 +21,8 @@
 
 - "Cardinality limit" outcomes now report which limit was exceeded. ([#3825](https://github.com/getsentry/relay/pull/3825))
 - Derive span browser name from user agent. ([#3834](https://github.com/getsentry/relay/pull/3834))
+- Redis pools for `project_configs`, `cardinality`, `quotas`, and `misc` usecases
+  can now be configured individually. ([#3859](https://github.com/getsentry/relay/pull/3859))
 
 **Internal**:
 

relay-config/src/config.rs

@@ -16,15 +16,14 @@ use relay_kafka::{
 };
 use relay_metrics::aggregator::{AggregatorConfig, FlushBatching};
 use relay_metrics::MetricNamespace;
-use relay_redis::RedisConfigOptions;
 use serde::de::{DeserializeOwned, Unexpected, Visitor};
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use uuid::Uuid;
 
 use crate::aggregator::{AggregatorServiceConfig, ScopedAggregatorConfig};
 use crate::byte_size::ByteSize;
 use crate::upstream::UpstreamDescriptor;
-use crate::{RedisConfig, RedisConnection};
+use crate::{create_redis_pools, RedisConfig, RedisConfigs, RedisPoolConfigs};
 
 const DEFAULT_NETWORK_OUTAGE_GRACE_PERIOD: u64 = 10;
 
@@ -1076,7 +1075,7 @@ pub struct Processing {
     pub kafka_validate_topics: bool,
     /// Redis hosts to connect to for storing state for rate limits.
     #[serde(default)]
-    pub redis: Option<RedisConfig>,
+    pub redis: Option<RedisConfigs>,
     /// Maximum chunk size of attachments for Kafka.
     #[serde(default = "default_chunk_size")]
     pub attachment_chunk_size: ByteSize,
@@ -1637,7 +1636,7 @@ impl Config {
         }
 
         if let Some(redis) = overrides.redis_url {
-            processing.redis = Some(RedisConfig::single(redis))
+            processing.redis = Some(RedisConfigs::Unified(RedisConfig::single(redis)))
         }
 
         if let Some(kafka_url) = overrides.kafka_url {
@@ -2356,34 +2355,15 @@ impl Config {
         &self.values.processing.topics.unused
     }
 
-    /// Redis servers to connect to, for rate limiting.
-    pub fn redis(&self) -> Option<(&RedisConnection, RedisConfigOptions)> {
-        let cpu_concurrency = self.cpu_concurrency();
+    /// Redis servers to connect to for project configs, cardinality limits,
+    /// rate limiting, and metrics metadata.
+    pub fn redis(&self) -> Option<RedisPoolConfigs> {
+        let redis_configs = self.values.processing.redis.as_ref()?;
 
-        let redis = self.values.processing.redis.as_ref()?;
-
-        let max_connections = redis
-            .options
-            .max_connections
-            .unwrap_or(cpu_concurrency as u32 * 2)
-            .max(crate::redis::DEFAULT_MIN_MAX_CONNECTIONS);
-
-        let min_idle = redis
-            .options
-            .min_idle
-            .unwrap_or_else(|| max_connections.div_ceil(crate::redis::DEFAULT_MIN_IDLE_RATIO));
-
-        let options = RedisConfigOptions {
-            max_connections,
-            min_idle: Some(min_idle),
-            connection_timeout: redis.options.connection_timeout,
-            max_lifetime: redis.options.max_lifetime,
-            idle_timeout: redis.options.idle_timeout,
-            read_timeout: redis.options.read_timeout,
-            write_timeout: redis.options.write_timeout,
-        };
-
-        Some((&redis.connection, options))
+        Some(create_redis_pools(
+            redis_configs,
+            self.cpu_concurrency() as u32,
+        ))
     }
 
     /// Chunk size of attachments in bytes.