Chapter 16. Creating caches with Data Grid Operator
Use Cache
CRs to add cache configuration with Data Grid Operator and control how Data Grid stores your data.
16.1. Data Grid caches
Cache configuration defines the characteristics and features of the data store and must be valid with the Data Grid schema. Data Grid recommends creating standalone files in XML or JSON format that define your cache configuration. You should separate Data Grid configuration from application code for easier validation and to avoid the situation where you need to maintain XML snippets in Java or some other client language.
To create caches with Data Grid clusters running on OpenShift, you should:
-
Use
Cache
CR as the mechanism for creating caches through the OpenShift front end. -
Use
Batch
CR to create multiple caches at a time from standalone configuration files. - Access Data Grid Console and create caches in XML or JSON format.
You can use Hot Rod or HTTP clients but Data Grid recommends Cache
CR or Batch
CR unless your specific use case requires programmatic remote cache creation.
Cache CRs
-
Cache
CRs apply to Data Grid service pods only. -
Each
Cache
CR corresponds to a single cache on the Data Grid cluster.
16.2. Creating caches with the Cache CR
Complete the following steps to create caches on Data Grid service clusters using valid configuration in XML or YAML format.
Procedure
-
Create a
Cache
CR with a unique value in themetadata.name
field. -
Specify the target Data Grid cluster with the
spec.clusterName
field. Name your cache with the
spec.name
field.NoteThe
name
attribute in the cache configuration does not take effect. If you do not specify a name with thespec.name
field then the cache uses the value of themetadata.name
field.-
Add a cache configuration with the
spec.template
field. Apply the
Cache
CR, for example:oc apply -f mycache.yaml cache.infinispan.org/mycachedefinition created
Cache CR examples
XML
apiVersion: infinispan.org/v2alpha1 kind: Cache metadata: name: mycachedefinition spec: clusterName: infinispan name: myXMLcache template: <distributed-cache mode="SYNC" statistics="true"><encoding media-type="application/x-protostream"/><persistence><file-store/></persistence></distributed-cache>
YAML
apiVersion: infinispan.org/v2alpha1 kind: Cache metadata: name: mycachedefinition spec: clusterName: infinispan name: myYAMLcache template: |- distributedCache: mode: "SYNC" owners: "2" statistics: "true" encoding: mediaType: "application/x-protostream" persistence: fileStore: ~
16.3. Updating caches with the Cache CR
You can control how Data Grid Operator handles modifications to the cache configuration in the Cache
CR.
Data Grid Operator attempts to update the cache configuration on the Data Grid Server at runtime. If the update fails, Data Grid Operator uses one of the following strategies:
- retain strategy
-
The Operator updates the status of the
Cache
CR toReady=False
. You can manually delete theCache
CR and create a new cache configuration. This is the default strategy. - recreate strategy
The Operator deletes the cache from the Data Grid cluster and creates a new cache with the latest
spec.template
value from theCache
CR.ImportantConfigure the
recreate
strategy only if your deployment can tolerate data loss.
Prerequisites
-
Have a valid
Cache
CR.
Procedure
Use the
spec.updates.strategy
field to set theCache
CR strategy.mycache.yaml
spec: updates: strategy: recreate
Apply changes to the
Cache
CR, for example:oc apply -f mycache.yaml
16.4. Adding persistent cache stores
You can add persistent cache stores to Data Grid service pods to save data to the persistent volume.
Data Grid creates a Single File cache store, .dat
file, in the /opt/infinispan/server/data
directory.
Procedure
Add the
<file-store/>
element to thepersistence
configuration in your Data Grid cache, as in the following example:<distributed-cache name="persistent-cache" mode="SYNC"> <encoding media-type="application/x-protostream"/> <persistence> <file-store/> </persistence> </distributed-cache>