Server configuration: max RPC request params (KB)

2025-05-28

Applies to: SQL Server Azure SQL Managed Instance

The max RPC request params (KB) server configuration option limits the amount of memory used by the remote procedure call (RPC) parameters for a single batched RPC call. A batched RPC call contains one or more statements that are submitted to the server as a single batch with its associated set of parameters.

By default, the server memory that is used for the parameters of batched RPC calls is unlimited. When the total memory consumed by RPC parameters is excessively large, the current server process might be terminated because of insufficient memory.

When the max RPC request params (KB) configuration is set to a nonzero value, the memory used by a single batched RPC call is limited to the specified value. If the RPC call exceeds the memory limit, it is terminated with error 701, severity 17, state 21, message: There is insufficient system memory in resource pool 'resource-pool-name' to run this query. Terminating the RPC call releases the memory consumed by the RPC parameters and avoids the risk of server process termination. For more information, see MSSQLSERVER_701.

Availability

This configuration option is available in the following SQL platforms and versions:

SQL Server 2019 (15.x) CU 26 and later versions
SQL Server 2022 (16.x) CU 13 and later versions
SQL Server 2025 (17.x) Preview
Azure SQL Managed Instance

Remarks

You can monitor the total server memory consumption by RPC parameters using sys.dm_os_memory_clerks, with USERSTORE_SXC as the memory clerk type, and using sys.dm_os_memory_objects, with MEMOBJ_PROCESSRPC as the memory object type.

If you observe that the USERSTORE_SXC memory clerk or the MEMOBJ_PROCESSRPC memory objects consume disproportionately large amounts of memory, consider the following mitigations:

Modify the max RPC request params (KB) server configuration to limit the amount of memory consumed by a single batch RPC call. The optimal value depends on the size of the parameter data used in RPC calls and the number of RPC calls executing concurrently. Set a larger value initially, then start reducing the value while monitoring memory consumption and the occurrence of out-of-memory errors (error 701, state 21) while RPC calls execute. The goal is to keep memory consumption under control while minimizing the occurrence of out-of-memory errors.
Split large RPC calls into smaller batches. For example, instead of using 100,000 INSERT statements in a single RPC call, issue 10 RPC calls with 10,000 statements in each call.
Avoid using RPC calls to insert data in bulk. Instead, use the bulk copy methods of the client driver, such as SqlBulkCopy for SqlClient in .NET or SQLServerBulkCopy for JDBC in Java. For more information, see Bulk Import and Export of Data (SQL Server).

Examples

A. Set the maximum RPC call parameter memory

The following example sets the maximum RPC parameter memory a single RPC call can consume to 1 MB.

EXECUTE sp_configure 'show advanced options', 1;
RECONFIGURE;
GO

EXECUTE sp_configure 'max RPC request params (KB)', 1024;
RECONFIGURE;
GO

B. Monitor current total and maximum RPC parameter memory

The following examples monitor the current total and the maximum memory consumed by RPC parameters:

SELECT SUM(pages_kb) / 1024. AS userstore_sxc_memory_mb
FROM sys.dm_os_memory_clerks
WHERE type = 'USERSTORE_SXC';

SELECT SUM(pages_in_bytes) / 1024. / 1024 AS total_processrpc_memory_mb,
       MAX(max_pages_in_bytes) / 1024. / 1024 AS max_processrpc_memory_mb
FROM sys.dm_os_memory_objects
WHERE type = 'MEMOBJ_PROCESSRPC';

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