CURLMOPT_MAX_HOST_CONNECTIONS(3) Library Functions Manual
NAME
CURLMOPT_MAX_HOST_CONNECTIONS - max number of connections to a single
host
SYNOPSIS
#include <curl/curl.h>
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_MAX_HOST_CONNECTIONS,
long max);
DESCRIPTION
Pass a long to indicate max. The set number is used as the maximum
amount of simultaneously open connections to a single host (a host
being the same as a hostname + port number pair). For each new session
to a host, libcurl might open a new connection up to the limit set by
CURLMOPT_MAX_HOST_CONNECTIONS(3). When the limit is reached, new
sessions are kept pending until a connection becomes available.
The default max value is 0, unlimited. This set limit is also used for
proxy connections, and then the proxy is considered to be the host for
which this limit counts.
When more transfers are added to the multi handle than what can be
performed due to the set limit, they are queued up waiting for their
chance. When that happens, the CURLOPT_TIMEOUT_MS(3) timeout is
inclusive of the waiting time, meaning that if you set a too narrow
timeout in such a case the transfer might never even start before it
times out.
Even in the queued up situation, the CURLOPT_CONNECTTIMEOUT_MS(3)
timeout is however treated as a per-connect timeout.
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.
DEFAULT
0
PROTOCOLS
This functionality affects all supported protocols
EXAMPLE
int main(void)
{
CURLM *m = curl_multi_init();
/* do no more than 2 connections per host */
curl_multi_setopt(m, CURLMOPT_MAX_HOST_CONNECTIONS, 2L);
}
AVAILABILITY
Added in curl 7.30.0
RETURN VALUE
Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION
if not.
SEE ALSO
CURLMOPT_MAXCONNECTS(3), CURLMOPT_MAX_TOTAL_CONNECTIONS(3)
libcurl 2024-08-05 CURLMOPT_MAX_HOST_CONNECTIONS(3)
curl 8.9.1 - Generated Thu Aug 8 09:09:20 CDT 2024