BMC Remedy Mid Tier recommendations
To maximize the performance and usability of BMC Remedy Mid Tier, the following configuration practices are recommended:
Activating Perform Check
Sync Cache eliminates the need for administrators to flush the entire mid-tier cache after a form, active link, menu, or other definition change on BMC Remedy AR System server. When this feature is activated, the mid tier cache is automatically synchronized with the changed objects. The check is performed at the interval selected in the Definition Change Check Interval field.
- In Mid Tier Configuration Tool, click Cache Settings.
On the Cache Settings page, make sure that the Sync in cluster check box is selected.
This activates Sync Cache.
An administrator can press the new Sync Cache button to have the changes synchronized immediately.
The Sync Cache operation synchronizes any of the following objects, if the changed timestamp on BMC Remedy AR System server is more recent than the cached item in the mid-tier cache:
- Active links
- Containers (guides, applications, web services)
- Menus (character menus)
Because the performance hit is minimal, Sync Cache completely removes and rebuilds the following cache items:
- Group data
- Role data
- Image objects
The Sync Cache option is not available in pre 7.5, patch 004 versions.
When the Pre-Load option is activated, the following items are loaded when the server is started (or restarted):
- Active links and menus in the AR System server, and all user facing forms (any form with an associated active link)
- All usage history data
- The preload process starts after a 10 second delay.
- Open the Mid Tier Configuration Tool and click AR Server Settings.
- Select the server to edit, and click Edit (If you are adding a server, click Add Server).
- Select the Pre-Load check box.
- Click Save.
Enabling Cache Persistence
You can enable faster retrieval of forms when the server is restarted by activating the Enable Cache Persistence option.
- In the Mid Tier Configuration Tool, click Cache Settings.
- Select the Enable Cache Persistence check box.
- Click Save Changes.
Clearing the cache and restarting the server
Use the followings steps to clear the cache and restart the server after implementing the setting changes in 66057.
- Shutdown the JSP engine.
- Remove the contents of the following mid tier directories:
- Start the JSP engine.
- Allow Pre-Load to complete processing.
- Allow end users access to the system.
Before moving to the next step, it is recommend to allow one to two days of normal system usage. Patch 004 provides functionality to update the statistics file (viewstats.dat) with the following information about forms and views access requests.
- After 1-2 days of usage, disable Pre-Load in mid-tier configuration tool by clearing the check box next to the AR server name on the AR Server Settings page.
- Stop the JSP engine.
- Start the JSP engine.
With Prefetch and Pre-Load disabled mid-tier will on startup use it's statistics file to quickly load up into memory from the disk cache only forms which users have really been accessing. This will allow for the most efficient use of mid-tier's in memory cache and the best form access performance for end users.
Using the mid tier with third-party load balancers
Remember the following tips when load balancing:
- To have multiple instances of a mid-tier web application work correctly in a load-balanced environment, configure the load balancer so that the mid-tier instance of the user's first HTTP servlet request is routed to the server that maintains affinity (stickiness) — the connection for the life of a session. "Session affinity" in this context refers to how requests from the same client (in a cluster of servers) are always routed back to the same server, eliminating the need to replicate session data such as HttpSession.
- On the JSP/Servlet engine, enable cookie-based session tracking (the default), as opposed to tracking by URL re-writing, which the mid tier does not support.
- The mid tier does not support failover. Failover to a backup mid tier invalidates the user's HTTP session on the failed mid tier. (Failover is not transparent to the user. They would see a 9201 "Session timeout or invalid" error in their browsers and would need to log in again.)
While BMC Remedy AR System supports the use of load balancers, BMC does not test or recommend a specific third-party load balancer. BMC supports BMC Remedy AR System within the environment, but not the configuration or debugging of a load balancer itself beyond generic interaction expectations of BMC Remedy AR System with any load balancer.