Configuring the Caching Service for HA
Configuring the Caching Service for HA
Zowe uses the Caching Service to centralize the state data persistent in high availability (HA) mode. The Caching Service supports three storage methods: inMemory
, VSAM
and redis
.
inMemory
This storage method is designed for quick start of the service and should be used only for single instance scenario and development or test purpose. Do not use it in production or high availability scenario.
To use this method, leave the
ZWE_CACHING_SERVICE_PERSISTENT
configuration blank in theinstance.env
configuration file. When this method is enabled, the Caching Service will not persist any data. Also, if you have multiple instances of Caching Service, the data will not be shared across these instances.VSAM
Note: Performance issues related to the VSAM data set have been observed, so it is recommended that you use this storage method for light workload. If heavy workload is expected on Zowe components, it is recommended that you use the
redis
storage method instead.Follow these steps oo use this method:
- Set the value of
ZWE_CACHING_SERVICE_PERSISTENT
toVSAM
in theinstance.env
configuration file. - Create a VSAM data set. See Creating a VSAM data set for instructions.
- In
instance.env
, configureZWE_CACHING_SERVICE_VSAM_DATASET
with the VSAM data set you created.
- Set the value of
redis
To enable this method, set the value of
ZWE_CACHING_SERVICE_PERSISTENT
toredis
in theinstance.env
configuration file. See Redis configuration for more information. To learn more about Caching Service, see Using the Caching Service.
If you are using zowe.yaml
configuration other than instance.env
, please check Configure component caching-service for configuration details.
#
Creating a VSAM data setYou can use the ZWECSVSM
JCL to create a VSAM data set and define required security configurations. The ZWECSVSM
JCL is provided as part of the PDS sample library SZWESAMP
that is delivered with Zowe.
Before you submit the ZWECSVSM
JCL, you must customize it and review it with a system programmer who is familiar with z/OS VSAM data set and storage.
The following variables are available in the JCL:
#dsname
This variable specifies the data set name that the
ZWECSVSM
JCL will create. Replace all occurrences of#dsname
with the data set name that you want to specify. This data set name is the value forZWE_CACHING_SERVICE_VSAM_DATASET
ininstance.env
.MODE
This variable specifies whether you would like to use Record Level Sharing (RLS) for your VSAM data set.
RLS
is recommended for Sysplex deployment.// SET MODE=NONRLS RLS or NONRLS
#storclas
If you use the
RLS
mode, a storage class is required. Replace#storclas
with your desired storage class name.#volume
If you set to use the
NONRLS
mode, a storage volume is required. Replace#volume
with you desired storage volume.
Note: The ZWECSVSM
JCL defines the key length and record length of the VSAM instance. If the key length and record length of this JCL is changed,
CACHING_STORAGE_VSAM_KEYLENGTH
and CACHING_STORAGE_VSAM_RECORDLENGTH
must be set in instance.env
to the new values.
Follow these steps:
Customize the
ZWECSVSM
JCL. Edit the variables at the beginning and in the middle of the JCL.Submit the
ZWECSVSM
JCL to create a VSAM data set.