> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-parallel-read-in-order-multi-part.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Changelog

<Update label="2026-10-09">
  **New Features**

  * Expose mark cache RAM ratio on the onprem cluster chart

  **Bug Fixes**

  * Version gate `log_readahead_serve_wait_timeout_ms` so pre-26.8 keepers do not crashloop
  * Hold `reserved_log_items` at 500000 below keeper 26.8
  * Define the text and vector index cache env vars, tiered by pod memory

  **Chores**

  * Version gate the 26.3/26.4 config constraints and profile settings
  * Mark RKE2 as a supported distribution in preflight
  * Align basic auth values with secret refs in airgap-management

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `26.4.1.2596` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.22166.1` |
  | `helm/clickhouse-operator-helm` | `1.22166.1` |
  | `helm/onprem-clickhouse-cluster` | `1.11.6` |
  | `airgap-management` | `1.175.3` |
  | `helm/airgap-management` | `1.175.3` |
  | `helm/preflight-check` | `1.38.7` |
  | `helm/support-bundle` | `1.12.0` |
</Update>

<Update label="2026-10-05">
  **New Features**

  * feat(airgap): Add more defaults to the private operator chart (#42613)
  * feat(airgap): Disable unsecure ports for keeper, added disableNonSecureKeeperInServerPorts (#42613)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `26.2.1.788` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.22166.1` |
  | `helm/clickhouse-operator-helm` | `1.22166.1` |
  | `helm/onprem-clickhouse-cluster` | `1.11.0` |
  | `airgap-management` | `1.175.0` |
  | `helm/airgap-management` | `1.175.0` |
  | `helm/preflight-check` | `1.38.6` |
  | `helm/support-bundle` | `1.12.0` |
</Update>

<Update label="2026-09-17">
  **New Features**

  * feat(operator): Support custom SecurityContext RunAsUser/RunAsGroup (#29314)
  * feat(chart): Add account.passwordSecretRef (#40842)
  * feat(airgap): Airgap Management support basic auth credentials via env vars and Secrets (#41128)
  * feat(chart): Add runKeeperInServer feature flag (#41572)
  * feat(chart): Add podSecurityContext for keeper and server (#41715)

  **Bug Fixes**

  * fix(onprem-chart): version gate `distributed_cache_write_request_max_tries` (#40809)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `26.2.1.704` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.21380.1` |
  | `helm/clickhouse-operator-helm` | `1.21380.1` |
  | `helm/onprem-clickhouse-cluster` | `1.10.0` |
  | `airgap-management` | `1.175.0` |
  | `helm/airgap-management` | `1.175.0` |
  | `helm/preflight-check` | `1.38.6` |
  | `helm/support-bundle` | `1.12.0` |
</Update>

<Update label="2026-09-03">
  **New Features**

  * feat(support-bundle): support multi-cluster collection in support bundles (#40604)
  * feat(operator): source the database default password from a k8s secret (#39984)

  **Bug Fixes**

  * bugfix(private): reject raw account password hashes (#40475)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `26.2.1.525` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.20930.1` |
  | `helm/clickhouse-operator-helm` | `1.20930.1` |
  | `helm/onprem-clickhouse-cluster` | `1.8.7` |
  | `airgap-management` | `1.173.2` |
  | `helm/airgap-management` | `1.173.2` |
  | `helm/preflight-check` | `1.38.4` |
  | `helm/support-bundle` | `1.12.0` |
</Update>

<Update label="2026-08-14">
  **New Features**

  * feat(data-plane-management): support markCacheConfiguration overrides (#39343)
  * feat(onprem-chart): support single-zone Keeper deployments (AIR-368) (#39075)
  * feat(preflight-checks): allow custom namespace override in Preflight Check (AIR-360) (#38969)
  * feat(support-bundle): allow custom namespace override in Support Bundles (AIR-360) (#38970)

  **Bug Fixes**

  * fix(platform): bump Go to 1.26 and patch SCA-flagged dependencies (#39300)
  * fix(operator): retry ClickHouseCluster updates on resourceVersion conflict (#38965)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `26.2.1.525` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.20441.1` |
  | `helm/clickhouse-operator-helm` | `1.20441.1` |
  | `helm/onprem-clickhouse-cluster` | `1.8.7` |
  | `airgap-management` | `1.173.2` |
  | `helm/airgap-management` | `1.173.2` |
  | `helm/preflight-check` | `1.38.4` |
  | `helm/support-bundle` | `1.11.3` |
</Update>

<Update label="2026-08-07">
  **New Features**

  * feat(onprem-chart): Promote ClickHouse server `26.2.1.525` to latest stable (previously `25.12.1.1651`)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `26.2.1.525` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.20229.1` |
  | `helm/clickhouse-operator-helm` | `1.20229.1` |
  | `helm/onprem-clickhouse-cluster` | `1.8.2` |
  | `airgap-management` | `1.172.2` |
  | `helm/airgap-management` | `1.172.2` |
  | `helm/preflight-check` | `1.38.3` |
  | `helm/support-bundle` | `1.11.2` |
</Update>

<Update label="2026-07-31.1">
  **Bug Fixes**

  * chore(operator): bump dependencies to address CVEs (#38353)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1651` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.20105.1` |
  | `helm/clickhouse-operator-helm` | `1.20105.1` |
  | `helm/onprem-clickhouse-cluster` | `1.6.3` |
  | `airgap-management` | `1.172.2` |
  | `helm/airgap-management` | `1.172.2` |
  | `helm/preflight-check` | `1.38.3` |
  | `helm/support-bundle` | `1.11.2` |
</Update>

<Update label="2026-07-28">
  **New Features**

  * feat(onprem-chart): make current s3.storage defaults AWS specific (#37034)
  * feat(onprem-chart): default server capabilities including SETFCAP (#37402)
  * feat(onprem-chart): Enable helm\_local=false on gcp with HELM\_REPOSITORY (#37342)
  * feat(onprem-chart): Enable helm\_local=false on aws with HELM\_REPOSITORY (#36438)

  **Bug Fixes**

  * fix(onprem-chart): use cloud-appropriate topology label on GCP (#37796)
  * fix(airgap-api): bump golang.org/x/text to v0.39.0 \[HIGH] (#38025)
  * fix(onprem-chart): unset obsolete default profile settings (#37487)
  * fix(onprem-chart): Annotation value in helm chart isn't a string (#37278)
  * fix(onprem-chart): address failing FIPS tests (#36831)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1651` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.20048.1` |
  | `helm/clickhouse-operator-helm` | `1.20048.1` |
  | `helm/onprem-clickhouse-cluster` | `1.6.3` |
  | `airgap-management` | `1.172.2` |
  | `helm/airgap-management` | `1.172.2` |
  | `helm/preflight-check` | `1.38.3` |
  | `helm/support-bundle` | `1.11.2` |
</Update>

<Update label="2026-07-10">
  **New Features**

  * feat(preflights): add plainRewritableDiskForSystemTables deprecation preflight check (#35974)

  **Bug Fixes**

  * fix(operator): keeper readiness probe fix on nocve images in strict mode (#36636)
  * fix(onprem-helm-chart): unset `isOnEmptyDir` when `hostPathBaseDirectory` is provided (#36669)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1618` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.19517.1` |
  | `helm/clickhouse-operator-helm` | `1.19517.1` |
  | `helm/onprem-clickhouse-cluster` | `1.4.0` |
  | `airgap-management` | `1.172.0` |
  | `helm/airgap-management` | `1.172.0` |
  | `helm/preflight-check` | `1.38.1` |
  | `helm/support-bundle` | `1.11.1` |
</Update>

<Update label="2026-06-24">
  **New Features**

  * feat(preflight): validate ClickHouseCluster namespace matches its name (#35650)
  * feat(airgap): validate ClickHouse SSD cache disk is local NVMe (#35454)
  * feat(airgap): add cloud toggle to preflight checks (AIR-98) (#35089)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1618` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.19063.1` |
  | `helm/clickhouse-operator-helm` | `1.19063.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.311` |
  | `airgap-management` | `1.165.1` |
  | `helm/airgap-management` | `1.165.1` |
  | `helm/preflight-check` | `1.36.0` |
  | `helm/support-bundle` | `1.11.0` |
</Update>

<Update label="2026-06-09">
  **New Features**

  * feat(airgap): expose plainRewritableDiskForSystemTables flag (#35033)
  * feat(operator): add arm64 builds (#34389)
  * feat(preflight): add cache ratio check \[AIR-127] (#34709)
  * feat(airgap): add Shared Catalog migration preflight check (#34708)
  * feat(onprem): Add ResourceQuota to enforce single ClickHouseCluster per namespace (#34615)

  **Bug Fixes**

  * fix(airgap): wait for CRD to be established before cluster install (#34834)
  * fix(onprem): allow 0 keeper replicas for compute-compute separated children (#34693)
  * fix(operator): pushed fips builds missing correct build args (#34600)
  * fix(onprem-clickhouse-cluster): pin deprecated feature flags to operator-expected defaults (#34417)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1497` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.18587.1` |
  | `helm/clickhouse-operator-helm` | `1.18587.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.311` |
  | `airgap-management` | `1.165.1` |
  | `helm/airgap-management` | `1.165.1` |
  | `helm/preflight-check` | `1.31.0` |
  | `helm/support-bundle` | `1.11.0` |
</Update>

<Update label="2026-05-28">
  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1497` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.18587.1` |
  | `helm/clickhouse-operator-helm` | `1.18587.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.298` |
  | `airgap-management` | `1.165.1` |
  | `helm/airgap-management` | `1.165.1` |
  | `helm/preflight-check` | `1.31.0` |
  | `helm/support-bundle` | `1.11.0` |
</Update>

<Update label="2026-05-27">
  **New Features**

  * feat(airgap): Add Git SHA to private docs (#34183)
  * feat(airgap): Support BackupConfiguration in Helm Chart (#33746)
  * feat(airgap): Add deprecated feature flags to preflight check (#33545)

  **Bug Fixes**

  * fix(docs): airgap single page doc rendering (#34288)
  * fix(airgap): Fix anchor links in private documentation (#34122)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1497` |
  | `clickhouse-keeper` | `26.2.1.258` |
  | `clickhouse-operator` | `main-1.18587.1` |
  | `helm/clickhouse-operator-helm` | `1.18587.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.298` |
  | `airgap-management` | `1.165.1` |
  | `helm/airgap-management` | `1.165.1` |
  | `helm/preflight-check` | `1.24.1` |
  | `helm/support-bundle` | `1.8.1` |
</Update>

<Update label="2026-05-21">
  **New Features**

  * feat(clickhouse-operator): FIPS compliance build flags and runtime support (#29677)
  * feat(onprem-clickhouse-cluster): add support to the gcp base config in the onprem helm chart (#33501)

  **Bug Fixes**

  * fix(onprem-clickhouse-cluster): disable enableDynamicSSDCacheConfiguration (#33700)
  * fix(onprem-clickhouse-cluster): remove unused `openssl.fips` settings (#33881))
  * fix(onprem-clickhouse-cluster): drop cloud.port from extraConfig when TLS required (#33548)
  * fix(clickhouse-operator): mark SsdCacheConfiguration.IsOnEmptyDir as optional (#33570)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1497` |
  | `clickhouse-keeper` | `26.1.1.1493` |
  | `clickhouse-operator` | `main-1.18587.1` |
  | `helm/clickhouse-operator-helm` | `1.18587.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.298` |
  | `airgap-management` | `1.165.1` |
  | `helm/airgap-management` | `1.165.1` |
  | `helm/preflight-check` | `1.24.1` |
  | `helm/support-bundle` | `1.8.1` |
</Update>

<Update label="2026-04-23">
  **Bug Fixes**

  * fix(onprem-helm-chart): allow storageClass parameters and allowedTopologies (#32776)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.12.1.1497` |
  | `clickhouse-keeper` | `26.1.1.1493` |
  | `clickhouse-operator` | `main-1.18231.1` |
  | `helm/clickhouse-operator-helm` | `1.18231.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.260` |
  | `airgap-management` | `1.165.1` |
  | `helm/airgap-management` | `1.165.1` |
  | `helm/preflight-check` | `1.24.1` |
  | `helm/support-bundle` | `1.8.1` |
</Update>

<Update label="2026-04-15">
  **New Features**

  * feat(airgap): enable Shared Catalog and Stateless Servers by default (#32481)
  * fix(airgap-management): use source cluster S3 connection for backup restore (#32612)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.10.1.7525` |
  | `clickhouse-keeper` | `26.1.1.1493` |
  | `clickhouse-operator` | `main-1.17847.1` |
  | `helm/clickhouse-operator-helm` | `1.17847.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.245` |
  | `airgap-management` | `1.165.1` |
  | `helm/airgap-management` | `1.165.1` |
  | `helm/preflight-check` | `1.24.1` |
  | `helm/support-bundle` | `1.8.1` |
</Update>

<Update label="2026-04-14">
  **New Features**

  * feat(airgap): Support Shared Catalog in onprem-clickhouse-cluster Helm Chart (#31779)
  * feat(airgap): Add stateless server support onprem-clickhouse-cluster Helm Chart (#32202)
  * feat(airgap): add support-bundle helm chart (#32271)
  * feat(airgap): bring airgap api into FIPS compliance (#31811)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.10.1.7525` |
  | `clickhouse-keeper` | `26.1.1.1493` |
  | `clickhouse-operator` | `main-1.17847.1` |
  | `helm/clickhouse-operator-helm` | `1.17847.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.234` |
  | `airgap-management` | `1.83.1` |
  | `helm/airgap-management` | `1.83.1` |
  | `helm/preflight-check` | `1.24.1` |
  | `helm/support-bundle` | `1.8.1` |
</Update>

<Update label="2026-04-13">
  **New Features**

  * feat(airgap): Support Shared Catalog in onprem-clickhouse-cluster Helm Chart (#31779)
  * feat(airgap): Add stateless server support onprem-clickhouse-cluster Helm Chart (#32202)
  * feat(airgap): add support-bundle helm chart (#32271)
  * feat(airgap): bring airgap api into FIPS compliance (#31811)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.10.1.7525` |
  | `clickhouse-keeper` | `26.1.1.1493` |
  | `clickhouse-operator` | `main-1.17847.1` |
  | `helm/clickhouse-operator-helm` | `1.17847.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.234` |
  | `airgap-management` | `1.83.1` |
  | `helm/airgap-management` | `1.83.1` |
  | `helm/preflight-check` | `1.24.1` |
  | `helm/support-bundle` | `1.8.1` |
</Update>

<Update label="2026-04-10">
  **New Features**

  * feat(airgap): add support-bundle helm chart (#32271)
  * feat(airgap): bring airgap api into FIPS compliance (#31811)
  * feat(airgap): Support Shared Catalog in onprem-clickhouse-cluster Helm Chart (#31779)

  **Component versions**

  | Component | Version |
  | - | - |
  | `clickhouse-server` | `25.10.1.7525` |
  | `clickhouse-keeper` | `26.1.1.1493` |
  | `clickhouse-operator` | `1.17847.1` |
  | `helm/onprem-clickhouse-cluster` | `1.1.234` |
  | `airgap-management` | `1.83.1` |
  | `helm/airgap-management` | `1.83.1` |
  | `helm/preflight-check` | `1.24.1` |
  | `helm/support-bundle` | `1.8.1` |
</Update>