curl/docs/libcurl/opts/CURLOPT_MAXLIFETIME_CONN.md
Daniel Stenberg eefcc1bda4
docs: introduce "curldown" for libcurl man page format
curldown is this new file format for libcurl man pages. It is markdown
inspired with differences:

- Each file has a set of leading headers with meta-data
- Supports a small subset of markdown
- Uses .md file extensions for editors/IDE/GitHub to treat them nicely
- Generates man pages very similar to the previous ones
- Generates man pages that still convert nicely to HTML on the website
- Detects and highlights mentions of curl symbols automatically (when
  their man page section is specified)

tools:

- cd2nroff: converts from curldown to nroff man page
- nroff2cd: convert an (old) nroff man page to curldown
- cdall: convert many nroff pages to curldown versions
- cd2cd: verifies and updates a curldown to latest curldown

This setup generates .3 versions of all the curldown versions at build time.

CI:

Since the documentation is now technically markdown in the eyes of many
things, the CI runs many more tests and checks on this documentation,
including proselint, link checkers and tests that make sure we capitalize the
first letter after a period...

Closes #12730
2024-01-23 00:29:02 +01:00

1.7 KiB

c SPDX-License-Identifier Title Section Source See-also
Copyright (C) Daniel Stenberg, <daniel.se>, et al. curl CURLOPT_MAXLIFETIME_CONN 3 libcurl
CURLOPT_FORBID_REUSE (3)
CURLOPT_FRESH_CONNECT (3)
CURLOPT_MAXAGE_CONN (3)
CURLOPT_TIMEOUT (3)

NAME

CURLOPT_MAXLIFETIME_CONN - max lifetime (since creation) allowed for reusing a connection

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_MAXLIFETIME_CONN,
                          long maxlifetime);

DESCRIPTION

Pass a long as parameter containing maxlifetime - the maximum time in seconds, since the creation of the connection, that you allow an existing connection to have to be considered for reuse for this request.

libcurl features a connection cache that holds previously used connections. When a new request is to be done, libcurl considers any connection that matches for reuse. The CURLOPT_MAXLIFETIME_CONN(3) limit prevents libcurl from trying too old connections for reuse. This can be used for client-side load balancing. If a connection is found in the cache that is older than this set maxlifetime, it is instead marked for closure.

If set to 0, this behavior is disabled: all connections are eligible for reuse.

DEFAULT

Default maxlifetime is 0 seconds (i.e., disabled).

PROTOCOLS

All

EXAMPLE

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

    /* only allow each connection to be reused for 30 seconds */
    curl_easy_setopt(curl, CURLOPT_MAXLIFETIME_CONN, 30L);

    curl_easy_perform(curl);
  }
}

AVAILABILITY

Added in 7.80.0

RETURN VALUE

Returns CURLE_OK.