chore: Update uvicorn to fix worker timeout issue (#690)

* chore: Update uvicorn to fix worker timeout issue

* changelog

* bumped resources for overrides test

* fix test asserts

Author: adwk67

CHANGELOG.md

@@ -12,6 +12,7 @@
 ### Changed
 
 - Use internal secrets for secret- and jwt-keys ([#686]).
+- Update uvicorn version and revert to default number of API workers ([#690]).
 
 ### Fixed
 
@@ -31,6 +32,7 @@
 [#685]: https://github.com/stackabletech/airflow-operator/pull/685
 [#686]: https://github.com/stackabletech/airflow-operator/pull/686
 [#687]: https://github.com/stackabletech/airflow-operator/pull/687
+[#690]: https://github.com/stackabletech/airflow-operator/pull/690
 
 ## [25.7.0] - 2025-07-23
 

docs/modules/airflow/pages/troubleshooting/index.adoc

@@ -29,16 +29,15 @@ See e.g. https://github.com/minio/minio/issues/20845[this MinIO issue] for detai
 == Setting API Workers
 
 In Airflow the webserver (called the API Server in Airflow 3.x+) can use multiple workers.
-This is determined by the environment variable `+AIRFLOW__API__WORKERS+` and is set by default to `4` in Airflow 2.x and `1` in Airflow 3.x+.
-The reason for this difference is that Airflow uses a backend library to manage child processes and in 3.x+ this library can cause child processes to be killed if a hard-coded startup timeout is exceeded.
-For most cases with Airflow 3.x+ a default of `1` should be sufficient, but if you run into performance issues and would like to add more workers, you can either modulate multiple worker processes at the level of webserver, keeping the default of a single worker per webserver:
+This is determined by the environment variable `+AIRFLOW__API__WORKERS+` and is set by default to `4`.
+For most cases the default should work without problem, but if you run into performance issues and would like to add more workers, you can either modulate multiple worker processes at the level of webserver, keeping the default value for each one:
 
 [source,yaml]
 ----
 webservers:
   roleGroups:
     default:
-      replicas: 2 # add a replica (with a single worker)
+      replicas: 2 # add a replica (with the default number of workers)
 ----
 
 or change the environment variable using `envOverrides`:
@@ -47,7 +46,7 @@ or change the environment variable using `envOverrides`:
 ----
 webservers:
   envOverrides:
-    AIRFLOW__API__WORKERS: 2 # something other than the default of 1
+    AIRFLOW__API__WORKERS: 6 # something other than the default
 ----
 
 TIP: Our strong recommendation is to increase the webserver replicas, with each webserver running a single worker, as this removes the risk of running into timeouts or memory issues.

rust/operator-binary/src/env_vars.rs

@@ -507,17 +507,6 @@ fn add_version_specific_env_vars(
                     ..Default::default()
                 },
             );
-            // Airflow 3.x uses fast-api as a backend: newer versions of uvicorn can
-            // cause issues with child processes. See discussion here: <https://github.com/apache/airflow/discussions/50170#discussioncomment-13265000>.
-            // This will be considered as part of this issue: <https://github.com/stackabletech/airflow-operator/issues/641>.
-            env.insert(
-                "AIRFLOW__API__WORKERS".into(),
-                EnvVar {
-                    name: "AIRFLOW__API__WORKERS".into(),
-                    value: Some("1".into()),
-                    ..Default::default()
-                },
-            );
         }
     } else {
         env.insert(

tests/templates/kuttl/overrides/10-install-airflow.yaml.j2

@@ -86,7 +86,7 @@ spec:
           min: 400m
           max: 800m
         memory:
-          limit: 2Gi
+          limit: 3Gi
     podOverrides:
       spec:
         containers:

tests/templates/kuttl/overrides/11-assert.yaml

@@ -7,13 +7,17 @@ commands:
   # Test envOverrides
   #
   - script: |
+      set -eu
+
       kubectl -n $NAMESPACE get sts airflow-celery-webserver-default -o yaml | yq -e '.spec.template.spec.containers[] | select (.name == "airflow") | .env[] | select (.name == "COMMON_VAR" and .value == "group-value")'
       kubectl -n $NAMESPACE get sts airflow-celery-webserver-default -o yaml | yq -e '.spec.template.spec.containers[] | select (.name == "airflow") | .env[] | select (.name == "GROUP_VAR" and .value == "group-value")'
       kubectl -n $NAMESPACE get sts airflow-celery-webserver-default -o yaml | yq -e '.spec.template.spec.containers[] | select (.name == "airflow") | .env[] | select (.name == "ROLE_VAR" and .value == "role-value")'
       kubectl -n $NAMESPACE get sts airflow-celery-webserver-default -o yaml | yq -e '.spec.template.spec.containers[] | select (.name == "airflow") | .env[] | select (.name == "credentialsSecret" and .value == "test-override")'
 
 
   - script: |
+      set -eu
+
       kubectl -n $NAMESPACE get sts airflow-celery-worker-default -o yaml | yq -e '.spec.template.spec.containers[] | select (.name == "airflow") | .env[] | select (.name == "COMMON_VAR" and .value == "group-value")'
       kubectl -n $NAMESPACE get sts airflow-celery-worker-default -o yaml | yq -e '.spec.template.spec.containers[] | select (.name == "airflow") | .env[] | select (.name == "GROUP_VAR" and .value == "group-value")'
       kubectl -n $NAMESPACE get sts airflow-celery-worker-default -o yaml | yq -e '.spec.template.spec.containers[] | select (.name == "airflow") | .env[] | select (.name == "ROLE_VAR" and .value == "role-value")'

tests/templates/kuttl/overrides/20-install-airflow2.yaml.j2

@@ -32,7 +32,7 @@ spec:
             - name: airflow
               resources:
                 limits:
-                  cpu: 810m
+                  cpu: 2000m
     config:
       resources:
         cpu:

tests/templates/kuttl/overrides/21-assert.yaml

@@ -4,5 +4,7 @@ kind: TestAssert
 timeout: 30
 commands:
 - script: |
+    set -eu
+
     kubectl -n $NAMESPACE get cm airflow-kubernetes-executor-pod-template -o json | jq -r '.data."airflow_executor_pod_template.yaml"' | yq -e '.spec.containers.[0].resources.limits | select (.cpu == "750m")'
     kubectl -n $NAMESPACE get cm airflow-kubernetes-executor-pod-template -o json | jq -r '.data."airflow_executor_pod_template.yaml"' | yq -e '.spec.containers[] | select (.name == "base") | .env[] | select (.name == "AIRFLOW__METRICS__STATSD_ON" and .value == "False")'