diff --git a/docs/guides/src/main/server/caching.adoc b/docs/guides/src/main/server/caching.adoc new file mode 100644 index 0000000000..879213d6ed --- /dev/null +++ b/docs/guides/src/main/server/caching.adoc @@ -0,0 +1,126 @@ +<#import "/templates/guide.adoc" as tmpl> +<#import "/templates/kc.adoc" as kc> +<#import "/templates/options.adoc" as opts> + +<@tmpl.guide +title="Configure distributed caches" +summary="Understand how to configure the caching layer" +includedOptions="cache cache-*"> + +Keycloak is designed for high availability and multi-node clustered setups. The current distributed cache implementation is built on top of https://infinispan.org[Infinispan], a high-performance, distributable in-memory data grid. + +All available cache options are build options, so they need to be applied to a `build` of Keycloak before starting. + +== Enable distributed caching +Caching is enabled per default when you start Keycloak in production mode, using the `start` command. This will automatically discover other Keycloak nodes in your network. To explicitly enable distributed infinispan caching, use: + +<@kc.build parameters="--cache=ispn"/> + +When you start Keycloak in development mode, using the `start-dev` command, Keycloak defaults to only use local caches using `--cache=local` instead. Using the `local` cache mode is intended only for development and testing purposes. + +== Configure Caches +Keycloak provides a cache configuration file with sensible defaults located at `conf/cache-ispn.xml`. + +The cache configuration is a regular https://infinispan.org/docs/stable/titles/configuring/configuring.html[Infinispan] configuration file. + +=== Overview: Cache types and Defaults + +.Local caches +Keycloak caches persistent data locally to avoid unnecessary database requests. The caches used are: + +* realms +* users +* authorization +* keys + +.Invalidation of local caches +Local caching improves performance, but adds a challenge in multi-node setups: When one Keycloak node updates data in the shared database, all other nodes need to be aware of it, so they invalidate that data from their caches. The `work` cache is used for sending these invalidation messages. + +.Authentication sessions +Authentication sessions are started when an unauthenticated user or service tries to login to Keycloak. The `authenticationSessions` distributed cache is used to save data during authentication of particular user. + +.User sessions +There are four distributed caches for sessions of authenticated users and services: + +* sessions +* clientSessions +* offlineSessions +* offlineClientSessions + +These caches are used to save data about user sessions, and clients attached to the sessions. + +.Password brute force detection +The `loginFailures` distributed cache is used to track data about failed login attempts. This cache is needed for the Brute Force Protection feature to work correctly in a multi-node Keycloak setup. + +.Action tokens +Action tokens are used for scenarios when a user needs to confirm an action asynchronously, for example in the emails sent by the forgot password flow. The `actionTokens` distributed cache is used to track metadata about action tokens. + +The following table gives an overview of the specific caches Keycloak uses. These caches are configured in `conf/cache-ispn.xml`: + +|==== +|Cache name|Cache Type|Description +|realms|Local|Cache persisted realm data +|users|Local|Cache persisted user data +|authorization|Local|Cache persisted authorization data +|keys|Local|Cache external public keys +|work|Replicated|Propagate invalidation messages across nodes +|sessions|Distributed|Caches user sessions, when user is authenticated +|authenticationSessions|Distributed|Caches authentication sessions, when user is authenticating +|offlineSessions|Distributed|Caches offline sessions +|clientSessions|Distributed|Caches sessions for each client a user is authenticated with +|offlineClientSessions|Distributed|Caches offline client sessions +|loginFailures|Distributed|keep track of failed logins, fraud detection +|actionTokens|Distributed|Caches action Tokens +|==== + +Local caches for realms, users and authorization are configured to have 10000 entries per default. The local key cache can hold up to 1000 entries per default and defaults to expire every 1h, so keys are forced to be periodically downloaded from external clients or identity providers. + +All distributed caches are set to have 2 owners per default, meaning 2 nodes having a copy of the specific cache entries. Non-owner nodes query the owners of a specific cache to obtain data. When both owner nodes are offline, all data gets lost. This usually leads to users being logged out at the next request and having to login again. + +=== Specify your own cache configuration file + +To specify your own cache configuration file, use: + +<@kc.build parameters="--cache-config-file=my-cache-file.xml"/> + +== Transport stacks +Transport stacks ensure that distributed cache nodes in a cluster communicate in a reliable fashion. Keycloak supports a wide range of transport stacks: + +<@opts.expectedValues option="cache-stack"/> + +To apply a specific cache stack, use: + +<@kc.build parameters="--cache-stack="/> + +The default stack is set to `UDP` when distributed caches are enabled. + +=== Available transport stacks +The following table shows transport stacks that are available without any further configuration than using the `--cache-stack` build option: +|=== +|Stack name|Transport protocol|Discovery +|tcp|TCP|MPING (uses UDP multicast). +|udp|UDP|UDP multicast +|kubernetes|TCP|DNS_PING +|=== + +=== Additional transport stacks +The following table shows transport stacks that are supported by Keycloak, but need some extra steps to work. Note that all of these are _not_ Kubernetes / OpenShift stacks, so you don't need to enable the "google" stack if you want to run Keycloak on top of Googles Kubernetes engine. In that case, use the `kubernetes` stack. +Instead, when you have a distributed cache setup running on AWS EC2 instances, you'd need to set the stack to `ec2`, because ec2 does not support a default discovery mechanism such as `UDP`. + +|=== +|Stack name|Transport protocol|Discovery +|ec2|TCP|NATIVE_S3_PING +|google|TCP|GOOGLE_PING2 +|azure|TCP|AZURE_PING +|=== + +For the cloud vendor specific stacks to work, you have to provide additional dependencies to Keycloak. You can find more information, including Links to repositories providing the additional dependencies, in the https://infinispan.org/docs/dev/titles/embedding/embedding.html#jgroups-cloud-discovery-protocols_cluster-transport[official Infinispan documentation]. + +To provide the dependencies to Keycloak, put the respective JAR in the `providers` directory and `build` Keycloak afterwards, using + +<@kc.build parameters="--cache-stack="/> + +=== Securing cache communication +The current Infinispan cache implementation should be secured by various security measures such as RBAC, ACLs and Transport stack encryption. Please refer to the https://infinispan.org/docs/dev/titles/security/security.html#[Infinispan security guide] for more information about securing cache communication. + + diff --git a/docs/guides/src/main/server/features.adoc b/docs/guides/src/main/server/features.adoc index ccac21f31d..1c1bbdbaab 100644 --- a/docs/guides/src/main/server/features.adoc +++ b/docs/guides/src/main/server/features.adoc @@ -1,6 +1,5 @@ <#import "/templates/guide.adoc" as tmpl> <#import "/templates/kc.adoc" as kc> -<#import "/templates/options.adoc" as opts> <@tmpl.guide title="Enabling and disabling features"