# Ray head gcs\_server crashes with SIGSEGV (exit code -11) during ElastiCache/Valkey primary failover — GCS-FT does not survive Redis primary switchover

**URL:** <https://discuss.ray.io/t/ray-head-gcs-server-crashes-with-sigsegv-exit-code-11-during-elasticache-valkey-primary-failover-gcs-ft-does-not-survive-redis-primary-switchover/23594>\
**Category:** Uncategorized\
**Created:** [July 29, 2026, 3:10am UTC](https://discuss.ray.io/t/ray-head-gcs-server-crashes-with-sigsegv-exit-code-11-during-elasticache-valkey-primary-failover-gcs-ft-does-not-survive-redis-primary-switchover/23594 "2026-07-29T03:10:21Z")\
**Posts on this page:** 1\
**Showing post:** 1

<div class="post-metadata">

**Author:** ![getarbind](https://avatars.discourse-cdn.com/v4/letter/g/a698b9/32.png) [@getarbind](https://discuss.ray.io/u/getarbind)\
**Post date:** [July 29, 2026, 3:10am UTC](https://discuss.ray.io/t/ray-head-gcs-server-crashes-with-sigsegv-exit-code-11-during-elasticache-valkey-primary-failover-gcs-ft-does-not-survive-redis-primary-switchover/23594/1 "2026-07-29T03:10:21Z")

</div>

During a controlled chaos test that forces an ElastiCache (Valkey 8.1) primary→replica failover, the Ray head container’s gcs\_server process crashes with signal 11 (SIGSEGV) approximately 10 seconds after the failover completes. This kills the entire Ray head pod (Kubernetes restarts it), causing ~30–60 s of Ray control-plane unavailability and load-test errors. We expected GCS-FT to transparently reconnect to the new primary via the ElastiCache master. DNS endpoint and continue.

Is Valkey 8.1 (ElastiCache) a supported GCS-FT backend at our Ray/KubeRay version? Are there known incompatibilities with the Valkey engine vs. Redis OSS ?

---

_[View the full topic](https://discuss.ray.io/t/ray-head-gcs-server-crashes-with-sigsegv-exit-code-11-during-elasticache-valkey-primary-failover-gcs-ft-does-not-survive-redis-primary-switchover/23594)._