You can persist HTTP sessions from WebSphere® Portal into a data grid.
About this task
Introducing
WebSphere DataPower XC10 Appliance into a WebSphere Portal
environment can be beneficial in the following scenarios:
Important: Although the following scenarios introduce benefits,
increased processor usage in the WebSphere Portal
tier can result from introducing WebSphere DataPower XC10 Appliance into
the environment.
- When session persistence is required.
For example, if
the session data from your custom portlets must stay available during
a WebSphere Portal Server
failure, you can persist the HTTP sessions to the WebSphere DataPower XC10 Appliance data
grid. Data replicates among many servers, increasing data availability.
- In a multiple data center topology.
If your topology
spans multiple data centers across different physical locations, you
can persist the WebSphere Portal
HTTP sessions to the WebSphere DataPower XC10 Appliance data grid. The sessions replicate across
data grids in the data centers. If a data center fails, the sessions
are rolled over to another data center that has a copy of the data
grid data.
- To lower memory requirements on the WebSphere Portal Server tier.
By
offloading session data to a remote tier of container servers, a subset
of sessions are on the WebSphere Portal
servers. This offload of data reduces the memory requirements on the WebSphere Portal Server tier.
Results
You can access the WebSphere Portal
Server, and HTTP session data for the configured custom portlets is
persisted to the data grid.
If the entire
data grid that is hosting the application session data is unreachable
from the web container client, the client instead uses the base web
container in
WebSphere Application Server for
session management. The data grid might be unreachable in the following
scenarios:
- A network problem between the Web container and the remote container
servers.
- The remote container server processes have been stopped.
The number of session references kept in memory, specified by
sessionTableSize parameter,
is still maintained when the sessions are stored in the base web container.
The least recently used sessions are invalidated from the web container
session cache when the
sessionTableSize value
is exceeded. If the remote data grid becomes available, sessions that
were invalidated from the web container cache can retrieve data from
the remote data grid and load the data into a new session. If the
entire remote data grid is not available and the session is invalidated
from the session cache, the user’s session data is lost. Because of
this issue, you should not shut down the entire production remote
data grid when the system is running under load.