Introduction

The release notes include important installation changes and known issues. They also highlight ways that you can take advantage of new features or enhancements to improve your product usage.

For more information, see the following related resources:

  • Changelog: A full list of changes, including the ability to compare previous patch and minor versions.
  • Upgrade guide: Steps to upgrade from the previous minor version to the current version.
  • Version reference: Information about Solo’s version support.

Breaking changes

Review details about the following breaking changes. To review when breaking changes were released, you can use the comparison feature of the changelog.

Upstream Prometheus upgrade

Gloo Mesh Enterprise includes a built-in Prometheus server to help monitor the health of your Gloo components. This release of Gloo upgrades the Prometheus community Helm chart from version 19.7.2 to 25.11.0. As part of this upgrade, upstream Prometheus changed the selector labels for the deployment, which requires recreating the deployment. To help with this process, the Gloo Helm chart includes a pre-upgrade hook that automatically recreates the Prometheus deployment during a Helm upgrade. This breaking change impacts upgrades from previous versions to version 2.4.10, 2.5.1, or 2.6.0 and later.

If you do not want the redeployment to happen automatically, you can disable this process by setting the prometheus.skipAutoMigration Helm value to true. For example, you might use Argo CD, which converts Helm pre-upgrade hooks to Argo PreSync hooks and causes issues. To ensure that the Prometheus server is deployed with the right version, follow these steps:

  1. Confirm that you have an existing deployment of Prometheus at the old Helm chart version of chart: prometheus-19.7.2.
      kubectl get deploy -n gloo-mesh prometheus-server -o yaml | grep chart
  2. Delete the Prometheus deployment. Note that while Prometheus is deleted, you cannot observe Gloo performance metrics.
      kubectl delete deploy -n gloo-mesh prometheus-server
  3. In your Helm values file, set the prometheus.skipAutoMigration field to true.
  4. Continue with the Helm upgrade of Gloo Mesh Enterprise. The upgrade recreates the Prometheus server deployment at the new version.

New feature gate for east-west routes in JWT policies

Now, you can use the applyToRoutes selector in JWT policies to select east-west service mesh routes.

Previously, you could only select ingress routes that were attached to a virtual gateway. The use of a virtual gateway for ingress routes required a Gloo Mesh Gateway license in addition to your Gloo Mesh Enterprise license. For a Mesh-only scenario, you previously had to use the applyToDestinations selector. This meant that the same JWT policy applied to the destinations no matter how traffic reached them.

Now, you can use applyToRoutes for east-west routes. This way, you have more flexibility in how a destination is protected. For example, you might have several external and internal routes that go to the same backing destination. To secure these routes with different JWT policies, you can use applyToRoutes instead of applyToDestinations.

Before you upgrade to 2.6:

  1. Check your existing JWT policies that use applyToRoutes selectors and note the routes that they apply to.
  2. Check your existing route tables with the routes that you previously noted.
  3. Determine whether JWT policies apply to east-west service mesh routes.
    • If a route table includes a workload selector, or if a route table omits both the virtual gateway and workload selector fields: The JWT policies apply to the east-west service mesh routes. This might conflict with other JWT policies that already select the backing destinations of these routes.
    • If the route tables do not include a workload selector (except in the case that the route table also does not include a virtual gateway): The JWT policies do not apply to the east-west service mesh routes.
  4. Decide how to address the potential impact of updating the behavior of the JWT policy applyToRoutes selector.
    • To prevent JWT policies from apply to east-west service mesh routes, choose from the following options:
      • Update your configuration. For example, you might use a different label to select routes. Or, you might make separate route tables with separate route labels for your ingress routes vs. east-west routes.
      • Disable the feature gate by upgrading your Gloo Helm release with the featureGates.EnableJWTPolicyEastWestRoute value set to false.
    • To start applying JWT policies to east-west service mesh routes: Continue to upgrade to version 2.6. In version 2.6 and later, the feature gate is enabled by default.

For more information, see the following resources:

Installation changes

In addition to comparing differences across versions in the changelog, review the following installation changes from the previous minor version to version 2.6.

Safe mode enabled by default

Starting in version 2.6.0, safe mode is enabled on the Gloo management server by default to ensure that the server translates input snapshots only if all input snapshots are present in Redis or its local memory. This way, translation only occurs based on a complete translation context that includes all workload clusters.

Enabling safe mode resolves a race condition that was identified in version 2.5.3, 2.4.11, and earlier that could be triggered during simultaneous restarts of the management plane and Redis, including an upgrade to a newer Gloo Mesh Enterprise version. If hit, this failure mode could lead to partial translations on the Gloo management server which could result in Istio resources being temporarily deleted from the output snapshots that are sent to the Gloo agents.

To learn more about safe mode, see Safe mode.

New features

Review the following new features that are introduced in version 2.6 and that you can enable in your environment.

I/O threads for Redis

A new Helm value redis.deployment.ioThreads was introduced to specify the number of I/O threads to use for the built-in Redis instance. Redis is mostly single threaded, however some operations, such as UNLINK or slow I/O accesses can be performed on side threads. Increasing the number of side threads can help improve and maximize the performance of Redis as these operations can run in parallel.

If you set I/O threads, the Redis pod must be restarted during the upgrade so that the changes can be applied. During the restart, the input snapshots from all connected Gloo agents are removed from the Redis cache. If you also update settings in the Gloo management server that require the management server pod to restart, the management server’s local memory is cleared and all Gloo agents are disconnected. Although the Gloo agents attempt to reconnect to send their input snapshots and re-populate the Redis cache, some agents might take longer to connect or fail to connect at all. To ensure that the Gloo management server halts translation until the input snapshots of all workload cluster agents are present in Redis, it is recommended to enable safe mode on the management server alongside updating the I/O threads for the Redis pod. For more information, see Safe mode. Note that in version 2.6.0 and later, safe mode is enabled by default.

To update I/O side threads in Redis as part of your Gloo Mesh Enterprise upgrade:

  1. Scale down the number of Gloo management server pods to 0.

      kubectl scale deployment gloo-mesh-mgmt-server --replicas=0 -n gloo-mesh

  2. Upgrade Gloo Mesh Enterprise and use the following settings in your Helm values file for the management server. Make sure to also increase the number of CPU cores to one core per thread, and add an additional CPU core for the main Redis thread. The following example also enables safe mode on the Gloo management server to ensure translation is done with the complete context of all workload clusters.

      
glooMgmtServer:
  safeMode: true
redis: 
  deployment: 
    ioThreads: 2
    resources: 
      requests: 
        cpu: 3
      limits: 
        cpu: 3

Gloo Insights

In version 2.6.0 and later, Gloo Mesh Enterprise comes with an insights engine that automatically analyzes your Istio and, if installed, Cilium setups for health issues. Then, Gloo shares these issues along with recommendations to harden your Istio and Cilium setups. The insights give you a checklist to address issues that might otherwise be hard to detect across your environment. For an overview of available insights, see Insights.

To enable insights generation, include the --set glooInsightsEngine.enabled=true setting when you upgrade your Gloo Helm installation.

Figure: Insights page

Feature changes

Review the following changes that might impact how you use certain features in your Gloo environment.

Improved Gloo UI

When you install or upgrade Gloo Mesh Enterprise to version 2.6.0 or later, the Gloo UI is redesigned to help you more quickly review the health and status of your Gloo environment. For example, the expanded Dashboard provides an at-a-glance overview of your environment by summarizing insights, health, status, inventories, security, and more in various cards. A new Inventory section provides pages that describe the health of registered clusters, discovered services, and nodes that make up your Gloo environment.

For more information about the expanded features in the new Gloo UI, see the Gloo UI overview.


Figure: Gloo UI dashboard

Improved error logging

The Gloo management server translates your Gloo custom resources into many underlying Istio resources. When the management server cannot translate a resource, it returns debug logs that vary in severity from errors to warnings or info.

In this release, the management server logs are improved in the following ways:

  • All translation errors are now logged at the debug level. This way, the management server logs are not cluttered by errors that do not impact the management server’s health.
  • Fixed a bug that caused many duplicate error logs. Now, you have fewer logs to sift through.

For example, you might have a service that does not select any existing workloads. This scenario might be intentional, such as if you use a CI/CD tool like ArgoCD to deploy your environment in phases. Translation does not complete until you update the service’s selector or create the workload. Previously, the translation error would show up many times in the management server logs, even though the situation is intentional and the management server is healthy and can translate other objects. Now, the translation error is logged less verbosely at the debug level.

You can still review translation errors in the following ways:

  • Translation errors and warnings are shown in the statuses of Gloo custom resources. For example, if a policy fails to apply to a route, you can review the warning in the policy and the route table statuses.
  • In the management server, enable debug logging by enabling the --verbose=true setting. Example command:
      kubectl patch deploy -n gloo-mesh gloo-mesh-mgmt-server --type "json" -p '[{"op":"add","path":"/spec/template/spec/containers/0/args/-","value":"--verbose=true"}]'

Known issues

The Solo team fixes bugs, delivers new features, and makes changes on a regular basis as described in the changelog. Some issues, however, might impact many users for common use cases. These known issues are as follows:

  • Cluster names: Do not use underscores (_) in the names of your clusters or in the kubeconfig context for your clusters.

  • OTel pipeline: FIPS-compliant builds are not currently supported for the OTel collector agent image.

  • Istio:

    • Due to a lack of support for the Istio CNI and iptables for the Istio proxy, you cannot run Istio (and therefore Gloo Mesh Enterprise) on AWS Fargate. For more information, see the Amazon EKS issue.
    • Istio 1.20 is supported only as patch version 1.20.1-patch1 and later. Do not use patch versions 1.20.0 and 1.20.1, which contain bugs that impact several Gloo Mesh Core features that rely on Istio ServiceEntries.
      • The WasmDeploymentPolicy Gloo CR is currently unsupported in Istio versions 1.18 and later.
      • For FIPS-compliant Solo distributions of Istio 1.17.2 and 1.16.4, you must use the -patch1 versions of the latest Istio builds published by Solo, such as 1.17.2-patch1-solo-fips for Solo distribution of Istio 1.17. These patch versions fix a FIPS-related issue introduced in the upstream Envoy code. In 1.17.3 and later, FIPS compliance is available in the -fips tags of regular Solo distributions of Istio, such as 1.17.3-solo-fips.