リリース

v1.18.0 adds overflow cluster affinities for hybrid cloud burst scheduling and a scheduling overcommit protection mechanism. Mandatory step: upgrade to v1.17.3+ before applying this release.

• securityAlpine base image updated to 3.23.4

  The base Alpine image moved from 3.23.3 to 3.23.4. No action needed beyond the normal upgrade, but if you pin image digests in your deployment, update them accordingly.

• breakingUpgrade to v1.17.3+ before moving to v1.18.x

  Before upgrading to v1.18.x, you must first be on v1.17.3+. Skipping this step will break the operator upgrade. Check your current version with `karmadactl version` and upgrade to v1.17.3+ first if you are behind.

• breakingDeprecated gRPC fields in scheduler-estimator require plugin updates

  Several deprecated gRPC fields in karmada-scheduler-estimator are now replaced: `resourceRequest` → `resourceRequestBytes`, `nodeAffinity` → `nodeAffinityBytes`, `tolerations` → `tolerationsBytes`. If you have custom estimator plugins or tooling that reads these fields directly, update them before upgrading. The old fields still exist in v1.18 but are deprecated and will be removed in a future release.

• breakingRemoved flags and metric labels will break existing configs

  Two flags removed from karmada-controller-manager: `--cluster-lease-duration` and `--cluster-lease-renew-interval-fraction`. Also, `Etcd.Local.InitImage` is gone from Karmada Init Configuration. If your deployment scripts or Helm values reference these, remove them before upgrading or the components will fail to start. Also check your Prometheus dashboards: the `cluster` and `cluster_name` metric labels are gone, replaced by `member_cluster`.

• enhancementCritical scheduler and eviction bug fixes

  Two significant scheduler bugs are fixed in this release. First, bindings with insufficient cluster replicas were retrying via exponential backoff (1–10s) instead of the correct 5-minute timer queue — workloads may have appeared stuck. Second, a race condition could silently drop graceful eviction tasks when multiple controllers modified the same ResourceBinding concurrently, meaning workloads might not have been evacuated from failing clusters. If you have observed unexplained scheduling delays or failed evictions, upgrade to v1.18.0 and re-examine affected workloads.

• enhancementEnable SchedulingOvercommitProtection in high-throughput clusters

  SchedulingOvercommitProtection (disabled by default via feature gate) closes the window where back-to-back scheduling decisions could over-commit a cluster's capacity before Pods are actually bound to nodes. Enable it in high-throughput environments where you see workloads going Pending due to resource exhaustion shortly after scheduling. Set `--feature-gates=SchedulingOvercommitProtection=true` on karmada-scheduler and karmada-scheduler-estimator once you've validated in staging.

• enhancementOverflow Cluster Affinities for hybrid cloud burst scheduling

  The new `overflowAffinities` field in PropagationPolicy/ClusterPropagationPolicy lets you define fallback cluster groups. The scheduler fills the primary group first, then spills to supplementary groups in order. On scale-down, replicas are reclaimed from supplementary groups first. Useful for IDC-primary / public-cloud-overflow patterns. This is a new API field — existing policies are unaffected unless you add it.

Karmada v1.17.2 is a patch release fixing scheduler misrouting bugs, operator reconciliation failures, and a Job replica assignment error — plus an Alpine base image bump for security.

• securityRebuild or pull updated images to get the Alpine 3.23.4 base

  The base image was bumped from Alpine 3.23.3 to 3.23.4. If you're running air-gapped or mirrored image setups, make sure to pull and mirror the new v1.17.2 images. Check Alpine's changelog for the specific CVEs addressed if your compliance process requires it.

• breakingScheduler backoffQ misrouting may have masked real scheduling failures

  Bindings with insufficient cluster replicas were incorrectly queued in backoffQ instead of unschedulableBindings. This means your scheduler may have been retrying workloads on an exponential backoff schedule rather than surfacing them as unschedulable. After upgrading, expect some previously silent failures to become visible in unschedulableBindings — review any workloads that seemed stuck or slow to schedule.

• enhancementUpgrade if you use karmada-operator with custom tolerations/affinity or multi-cluster Jobs

  Two high-impact fixes landed here: operator-managed deployments were silently ignoring tolerations and affinity configs, which could cause pods to land on unintended nodes. And Job completion counts were being assigned incorrectly across clusters, which could corrupt Job semantics in distributed workloads. Both are straightforward regressions worth patching immediately if either feature is in use.

Karmada v1.16.5 is a focused patch release fixing scheduler queue misrouting, Job replica assignment errors, and operator reconciliation failures, plus an Alpine base image bump.

• securityAlpine 3.23.4 base image — rebuild and redeploy your Karmada components

  The Alpine bump from 3.23.3 to 3.23.4 addresses upstream security concerns. If you're running custom-built Karmada images or have image scanning in your pipeline, update your base images accordingly. The official images in this release already include the updated base.

• breakingScheduler queue misrouting causes stalled workloads — patch immediately

  The backoffQ vs unschedulableBindings misrouting bug means workloads with insufficient cluster replicas may have been stuck in the wrong queue, causing unexpected scheduling delays or failures. If you've seen bindings that appear perpetually pending despite enough cluster capacity becoming available, this fix directly addresses that. Upgrade to v1.16.5 and check for any bindings that are stuck — they should reschedule automatically after the upgrade.

• breakingJob completions were assigned to wrong clusters — review existing Job distributions

  The Job completion replica assignment bug could have led to incorrect work distribution across member clusters. Jobs that ran on this version may have had skewed completion counts per cluster. After upgrading, inspect any multi-cluster Jobs that were scheduled on v1.16.4 to verify their completion semantics were not affected in production.

Karmada v1.15.8 is a targeted bug-fix patch addressing scheduler queue misrouting, missing cluster info in events, and an operator reconciliation failure. Alpine base image bumped for security.

• securityRebuild and redeploy to pick up alpine:3.23.4 patches

  The alpine base image bump from 3.23.3 to 3.23.4 addresses unspecified security concerns. If you're running custom Karmada images built from the upstream base, rebuild against the new base. If you're using official images, pulling v1.15.8 is sufficient.

• breakingScheduler queue misrouting can cause workloads to be stuck — patch immediately

  The backoffQ bug is particularly dangerous in production: when a binding hits insufficient replicas, it gets retried with exponential backoff instead of being placed in unschedulableBindings where it belongs. This means your workloads silently wait longer than expected before rescheduling. If you're running ClusterAffinities with replica constraints, upgrade to v1.15.8 — don't wait on this one.

• enhancementOperator idempotency fix prevents init reconciliation crashes on restarts

  The non-idempotent secret creation in karmada-operator meant that if the operator restarted mid-initialization, reconciliation would fail. This is now fixed with an idempotent approach. If you've been seeing operator init failures after pod restarts or rolling updates, this patch resolves the root cause.

Karmada v1.16.4 patches three bugs: a broken certificate rotation loop in karmada-agent, a Helm chart rendering failure on upgrades, and a race condition that silently dropped graceful eviction tasks.

• securityCertificate rotation was silently broken — rotate certificates after upgrading

  The SignerName mismatch meant that agent certificate rotation CSRs were never approved, so agent certificates were quietly expiring without renewal. After upgrading to v1.16.4, check the remaining validity of your karmada-agent certificates across all member clusters and manually trigger rotation if any are close to expiry. Don't assume rotation was working before this fix.

• breakingEviction race condition could leave workloads stranded on failing clusters

  If you run multiple controller replicas or have high-churn ResourceBindings, the race condition fixed in this release means your workloads may have silently failed to evacuate from tainted or unhealthy clusters. Upgrade to v1.16.4 immediately and verify that any in-flight eviction tasks complete. Check cluster taints and ResourceBinding status after upgrading to confirm nothing was left behind.

• breakingHelm chart upgrades with unrendered ca_crt will break TLS — re-run your upgrades

  The '{{ ca_crt }}' template variable was not being rendered during Helm upgrades, which would produce invalid TLS configuration silently. If you upgraded via Helm between v1.16.3 and this release, inspect your deployed chart values and secrets to confirm ca_crt is properly populated. Re-apply or re-upgrade using v1.16.4 if you suspect the broken rendering affected your environment.

Karmada v1.15.7 patches three bugs: a cert rotation deadlock in the agent, a Helm chart rendering failure on upgrade, and a race condition that silently dropped graceful eviction tasks.

• securityAudit agent certificates for expiry before upgrading

  The cert rotation bug could have left agents with expired certificates, creating an outage risk or a gap where mTLS wasn't enforced. Before upgrading, check the NotAfter field on agent certs. Post-upgrade, confirm the cert_rotation_controller and agent_csr_approving are now operating with matching SignerNames and that pending CSRs get approved.

• breakingCheck if cert rotation has been silently failing in your agents

  If your karmada-agent has been running for a while without certificate renewal, the SignerName mismatch bug means CSRs were never approved and certs may be expired or near expiry. After upgrading to v1.15.7, verify agent certificate validity and manually trigger rotation if needed. This is especially urgent in long-running clusters where cert TTLs are short.

• breakingSilent eviction failures may have left workloads on bad clusters — audit now

  The race condition in graceful eviction means any cluster that was tainted or marked unhealthy while multiple controllers were active may not have had its workloads evacuated. Before upgrading, check ResourceBinding and ClusterResourceBinding objects for stale taints or pending eviction conditions that were never resolved. Post-upgrade, re-trigger eviction for any affected bindings.

Karmada v1.15.6 is a critical bug-fix release addressing race conditions, scheduler panics, and CronFederatedHPA failures that could impact production stability.

• securityBase image security update included

  Alpine base image updated to 3.23.3 which may include security patches. Review your container scanning results after upgrade and update any custom images based on Karmada components.

• breakingCritical scheduler stability fixes require immediate update

  The scheduler panic fix and backoff queue corrections address critical stability issues that could cause service disruptions. Plan immediate upgrade for production environments running multi-cluster workloads with spread constraints or high scheduling volumes.

• enhancementCronFederatedHPA reliability improvements

  If using CronFederatedHPA for autoscaling, this release fixes scale-up failures when replicas field is missing. Update to ensure consistent autoscaling behavior across your federated deployments.