Disable gRPC compression (grafana#4429)

Our benchmark suggests that without compression, queriers and distributors use less CPU and memory.

This setting is configured at the client end.
That is, in the querier and in the ingester and metrics_generator clients of the distributor.

CHANGELOG.md

@@ -1,5 +1,19 @@
 ## main / unreleased
 
+* [CHANGE] Disable gRPC compression in the querier and distributor for performance reasons [#4429](https://github.com/grafana/tempo/pull/4429) (@carles-grafana)
+  If you would like to re-enable it, we recommend 'snappy'. Use the following settings:
+```
+ingester_client:
+    grpc_client_config:
+        grpc_compression: "snappy"
+metrics_generator_client:
+    grpc_client_config:
+        grpc_compression: "snappy"
+querier:
+    frontend_worker:
+        grpc_client_config:
+            grpc_compression: "snappy"
+```
 * [CHANGE] **BREAKING CHANGE** Add maximum spans per span set. Users can set `max_spans_per_span_set` to 0 to obtain the old behavior. [#4275](https://github.com/grafana/tempo/pull/4383) (@carles-grafana)
 * [CHANGE] slo: include request cancellations within SLO [#4355] (https://github.com/grafana/tempo/pull/4355) (@electron0zero)
   request cancellations are exposed under `result` label in `tempo_query_frontend_queries_total` and `tempo_query_frontend_queries_within_slo_total` with `completed` or `canceled` values to differentiate between completed and canceled requests.

cmd/tempo/app/config.go

@@ -116,9 +116,9 @@ func (c *Config) RegisterFlagsAndApplyDefaults(prefix string, f *flag.FlagSet) {
 
 	// Everything else
 	flagext.DefaultValues(&c.IngesterClient)
-	c.IngesterClient.GRPCClientConfig.GRPCCompression = "snappy"
+	c.IngesterClient.GRPCClientConfig.GRPCCompression = ""
 	flagext.DefaultValues(&c.GeneratorClient)
-	c.GeneratorClient.GRPCClientConfig.GRPCCompression = "snappy"
+	c.GeneratorClient.GRPCClientConfig.GRPCCompression = ""
 	c.Overrides.RegisterFlagsAndApplyDefaults(f)
 
 	c.Distributor.RegisterFlagsAndApplyDefaults(util.PrefixConfig(prefix, "distributor"), f)

modules/querier/config.go

@@ -76,7 +76,7 @@ func (cfg *Config) RegisterFlagsAndApplyDefaults(prefix string, f *flag.FlagSet)
 		GRPCClientConfig: grpcclient.Config{
 			MaxRecvMsgSize:  100 << 20,
 			MaxSendMsgSize:  16 << 20,
-			GRPCCompression: "gzip",
+			GRPCCompression: "",
 			BackoffConfig: backoff.Config{ // the max possible backoff should be lesser than QueryTimeout, with room for actual query response time
 				MinBackoff: 100 * time.Millisecond,
 				MaxBackoff: 1 * time.Second,