Network Deployment (Distributed operating systems), v8.0 > Establishing high availability > Configure core groups
Configure core group IP caching
The caching of name-to-IP address information can be performed at many levels within the network communication software stack. These levels include within the operating system, the JVM, and within the product components, such as core groups. Core groups use caching to reduce the overhead that is associated with IP address name lookup. We can adjust the interval at which a core group IP cache is cleared. By default, a core group cache is cleared every 60 minutes. We can determine the correct time interval for the environment. You want to change the length of time that IP addresses are retained in a core group cache.
To change how frequently a core group cache is cleared:
Procedure
- In the admin console, click...
Servers > Core Groups > Core group settings > core_group_name.
- In the Additional Properties > Custom properties.
- Change the value specified for the IBM_CS_IP_REFRESH_MINUTES custom property. A core group cache cannot be cleared more frequently then once a minute.
If the IBM_CS_IP_REFRESH_MINUTES property already exists, click on the property name and in the Value field, specify the length of time, in minutes, to wait before a core group cache is cleared.
If this property does not already exist, click New and create it:
- In the Name field, specify IBM_CS_IP_REFRESH_MINUTES.
- In the Value field specify the length of time, in minutes, to wait before a core group cache is cleared.
- Click OK and then click Review.
- Select Synchronize changes with nodes, and then click Save.
- Restart all members of the core group.
Results
After the servers restart, all of the core group members run with the new discovery protocol setting.
Core groups (high availability domains)
Set up a high availability environment