docs: mark serverless as deprecated (#4017)

* docs: mark serverless as deprecated

* Changelog + readme

CHANGELOG.md

@@ -1,4 +1,5 @@
 ## main / unreleased
+* [CHANGE] **BREAKING CHANGE** The Tempo serverless is now deprecated and will be removed in an upcoming release [#4017](https://github.com/grafana/tempo/pull/4017/) @electron0zero
 * [CHANGE] **BREAKING CHANGE** Change the AWS Lambda serverless build tooling output from "main" to "bootstrap". Refer to https://aws.amazon.com/blogs/compute/migrating-aws-lambda-functions-from-the-go1-x-runtime-to-the-custom-runtime-on-amazon-linux-2/ for migration steps [#3852](https://github.com/grafana/tempo/pull/3852) (@zatlodan)
 * [CHANGE] Add throughput and SLO metrics in the tags and tag values endpoints [#4148](https://github.com/grafana/tempo/pull/4148) (@electron0zero)
 * [CHANGE] tempo-cli: add support for /api/v2/traces endpoint [#4127](https://github.com/grafana/tempo/pull/4127) (@electron0zero)

cmd/tempo-serverless/readme.md

@@ -1,5 +1,7 @@
 # tempo-serverless
 
+## NOTE: The Tempo serverless is now deprecated and will be removed in an upcoming release.
+
 This folder is intended to wrap a simple handler for searching backend storage for traces. Subfolders 
 `./cloud-run` and `./lambda` contain specific code necessary to run this handler in the respective
 environments.

docs/sources/tempo/configuration/_index.md

@@ -739,6 +739,7 @@ querier:
         # Timeout for search requests
         [query_timeout: <duration> | default = 30s]
 
+        # NOTE: The Tempo serverless feature is now deprecated and will be removed in an upcoming release.
         # A list of external endpoints that the querier will use to offload backend search requests. They must
         # take and return the same value as /api/search endpoint on the querier. This is intended to be
         # used with serverless technologies for massive parallelization of the search path.

docs/sources/tempo/operations/backend_search.md

@@ -113,6 +113,10 @@ querier:
 
 With serverless technologies:
 
+{{< admonition type="caution" >}}
+The Tempo serverless feature is now deprecated and will be removed in an upcoming release.
+{{< /admonition >}}
+
 {{< admonition type="note" >}}
 Serverless can be a nice way to reduce cost by using it as spare query capacity.
 However, serverless tends to have higher variance then simply allowing the queriers to perform the searches themselves.
@@ -172,6 +176,10 @@ query_frontend:
 
 ### Serverless environment
 
+{{< admonition type="caution" >}}
+The Tempo serverless feature is now deprecated and will be removed in an upcoming release.
+{{< /admonition >}}
+
 Serverless isn't required, but with larger loads, serverless can be used to reduce costs.
 Tempo has support for Google Cloud Run and AWS Lambda.
 In both cases, you can use the following

docs/sources/tempo/operations/serverless_aws.md

@@ -9,6 +9,10 @@ weight: 95
 
 # Search with AWS Lambda
 
+{{< admonition type="caution" >}}
+The Tempo serverless feature is now deprecated and will be removed in an upcoming release.
+{{< /admonition >}}
+
 This document explains how to set up AWS Lambda for serverless backend search.
 Read [improve search performance]({{< relref "./backend_search" >}}) for more guidance on configuration options for backend search.
 

docs/sources/tempo/operations/serverless_gcp.md

@@ -9,6 +9,10 @@ alias:
 
 # Search with Google Cloud Run
 
+{{< admonition type="caution" >}}
+The Tempo serverless feature is now deprecated and will be removed in an upcoming release.
+{{< /admonition >}}
+
 This document walks you through setting up a Google Cloud Run for serverless backend search.
 For more guidance on configuration options for full backend search [check here]({{< relref "./backend_search" >}}).