CURLMOPT_MAXCONNECTS - size of connection cache

#include <curl/curl.h>
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAXCONNECTS, long max);

Pass a long indicating the max. The set number is used as the maximum amount of simultaneously open connections that libcurl may keep in its connection cache after completed use. By default libcurl enlarges the size for each added easy handle to make it fit 4 times the number of added easy handles.

By setting this option, you can prevent the cache size from growing beyond the limit set by you.

When the cache is full, curl closes the oldest one in the cache to prevent the number of open connections from increasing.

This option is for the multi handle's use only, when using the easy interface you should instead use the CURLOPT_MAXCONNECTS(3) option.

See CURLMOPT_MAX_TOTAL_CONNECTIONS(3) for limiting the number of active connections.

Changing this value when there are transfers in progress is possible, and the new value is then used the next time checks are performed. Lowering the value does however not close down any active transfers, it simply does not allow new ones to get made.



int main(void)
  CURLM *m = curl_multi_init();
  /* only keep 10 connections in the cache */
  curl_multi_setopt(m, CURLMOPT_MAXCONNECTS, 10L);

Added in 7.16.3

Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION if not.


2024-05-22 libcurl