Virtual Memory

For the best performance, the Meridian application server needs to allocate sufficient memory for two purposes:

• A database cache for each active vault on the server
• Session data for each active user connected to a vault on the server.

If there is not sufficient physical memory for these purposes, together with all of the other applications running on the server, virtual memory is used to store the data temporarily on disk, which is much slower than physical memory and reduces system performance. This is why we recommend a server dedicated for use by Meridian as described in Dedicated Server.

To optimize virtual memory usage, there are several things you can do:

• Ensure that the Windows page file is large enough to meet the needs of all applications running on the server. We recommend that it be at least as large as the installed physical RAM on the server. We highly recommend that you assign the page file to a different drive than the drive where the Meridian vaults are located.
• Determine how much actual virtual memory is requested by Meridian by monitoring the AMEDMW instance of the Virtual Bytes counter of the Process object with Performance Monitor as described in Configuring the Windows Performance Monitor. Also monitor the Available Mbytes counter of the Memory object.

• If the amount of virtual memory used by Meridian approaches the amount of physical memory before the maximum expected number of users is reached, reduce the amount of memory allocated to database caches so that it can be used to accommodate more users.

  To adjust the database caches:

  1. Start using the system with a conservative number of users. Use Performance Monitor as described in step 2 to monitor the amount of virtual memory requested by Meridian during peak production hours.
  2. If Available Mbytes drops below 300 MB before the maximum virtual memory consumption is reached, reduce the Maximum Cache Size option of one or more vaults to free memory as described in Configure the MaximumCacheSize Setting.
  3. Monitor the amount of virtual memory used as additional users are allowed access to the system.
  4. Repeat steps a through c until all users are connected to vaults.

  If reducing the cache sizes causes the performance to become unacceptable, you should consider switching to a newer version or different edition of Windows Server, if possible, to access additional physical and virtual memory.