Size of shared memory for caching routine buffers.

[config]    routines=n      or  routines=n1, n2, n3, n4, n5, n6

You can specify the amount of memory to allocate for caching routine buffers in two ways — either specifying a single value or specifying values for all six buffer sizes.

You can specify only a single value, n, for the total size, in megabytes, of shared memory that InterSystems IRIS allocates for routine buffers. InterSystems IRIS divides this memory into the various buffer sizes for optimum performance.

Or you can specify the amount of memory to allocate for each routine buffer size. If you use this format, you must specify all 6 values (some of them can be 0). If fewer than 6 are given, InterSystems IRIS reverts to the first format using n=n1.

If a non-zero memory size is specified for any buffer size, the minimum number of buffers allocated for that size is 430. Therefore, the actual memory allocated for buffers of a given size could be bigger than configured. Because the InterSystems IRIS system requires 64K buffers, at least the minimum number of 64K buffers is always allocated even if 0 is specified.

The total number of allocated buffers is limited to 65528. If the number of buffers allocated exceeds this number, it is reduced to the maximum. The total amount of shared memory space on a 64–bit system cannot exceed 1023 MB.

routines=256

Allocate 256 MB for routine buffers, divided into various sizes by an internal formula.

routines=0

To allocate a minimum number of buffers, enter a single value of 0.

The default is 0, but InterSystems IRIS allocates a minimum amount of buffer space according to an internal formula. Minimum number of routine buffers for each size is 430 (if a smaller number is specified, the system adjusts up to 430). Total number of buffers cannot exceed 65528. Total amount of shared memory space on a 64–bit system cannot exceed 1023 MB.

For routines=n, InterSystems IRIS allocates a minimum of 35 MB. The maximum value depends on how much shared memory is allocated for global buffers and other uses. The total shared memory size cannot exceed 1023 MB. For routines=n1,n2,n3,n4,n5,n6, values other than 0 are subject to a minimum value of 300. The total number of buffers cannot exceed 65528.

On the page System Administration > Configuration > System Configuration > Memory and Startup, select the option to Configure Memory Settings Manually. In the Memory Allocated for Routine Cache (MB) field, enter a number of megabytes. See Memory and Startup Settings in the “Configuring InterSystems IRIS” chapter of the System Administration Guide for more information about allocating memory for routine buffers using the management portal.