SSL_CTX_SESS_NUMBER(3) | Library Functions Manual | SSL_CTX_SESS_NUMBER(3)

# NAME

`SSL_CTX_sess_number`, `SSL_CTX_sess_connect`, `SSL_CTX_sess_connect_good`, `SSL_CTX_sess_connect_renegotiate`, `SSL_CTX_sess_accept`, `SSL_CTX_sess_accept_good`, `SSL_CTX_sess_accept_renegotiate`, `SSL_CTX_sess_hits`, `SSL_CTX_sess_cb_hits`, `SSL_CTX_sess_misses`, `SSL_CTX_sess_timeouts`, `SSL_CTX_sess_cache_full` — obtain session cache statistics

# SYNOPSIS

library “libssl” libcrypto
`#include <openssl/ssl.h>`

long
`SSL_CTX_sess_number`(SSL_CTX *ctx);

long
`SSL_CTX_sess_connect`(SSL_CTX *ctx);

long
`SSL_CTX_sess_connect_good`(SSL_CTX *ctx);

long
`SSL_CTX_sess_connect_renegotiate`(SSL_CTX *ctx);

long
`SSL_CTX_sess_accept`(SSL_CTX *ctx);

long
`SSL_CTX_sess_accept_good`(SSL_CTX *ctx);

long
`SSL_CTX_sess_accept_renegotiate`(SSL_CTX *ctx);

long
`SSL_CTX_sess_hits`(SSL_CTX *ctx);

long
`SSL_CTX_sess_cb_hits`(SSL_CTX *ctx);

long
`SSL_CTX_sess_misses`(SSL_CTX *ctx);

long
`SSL_CTX_sess_timeouts`(SSL_CTX *ctx);

long
`SSL_CTX_sess_cache_full`(SSL_CTX *ctx);

# DESCRIPTION

`SSL_CTX_sess_number`() returns the current number of sessions in the internal session cache.

`SSL_CTX_sess_connect`() returns the number of started SSL/TLS handshakes in client mode.

`SSL_CTX_sess_connect_good`() returns the number of successfully established SSL/TLS sessions in client mode.

`SSL_CTX_sess_connect_renegotiate`() returns the number of started renegotiations in client mode.

`SSL_CTX_sess_accept`() returns the number of started SSL/TLS handshakes in server mode.

`SSL_CTX_sess_accept_good`() returns the number of successfully established SSL/TLS sessions in server mode.

`SSL_CTX_sess_accept_renegotiate`() returns the number of started renegotiations in server mode.

`SSL_CTX_sess_hits`() returns the number of successfully reused sessions. In client mode a session set with SSL_set_session(3) successfully reused is counted as a hit. In server mode a session successfully retrieved from internal or external cache is counted as a hit.

`SSL_CTX_sess_cb_hits`() returns the number of successfully retrieved sessions from the external session cache in server mode.

`SSL_CTX_sess_misses`() returns the number of sessions proposed by clients that were not found in the internal session cache in server mode.

`SSL_CTX_sess_timeouts`() returns the number of sessions proposed by clients and either found in the internal or external session cache in server mode, but that were invalid due to timeout. These sessions are not included in the `SSL_CTX_sess_hits`() count.

`SSL_CTX_sess_cache_full`() returns the number of sessions that were removed because the maximum session cache size was exceeded.

# SEE ALSO

ssl(3), SSL_CTX_ctrl(3), SSL_CTX_sess_set_cache_size(3), SSL_CTX_set_session_cache_mode(3), SSL_set_session(3)

# HISTORY

`SSL_CTX_sess_number`(), `SSL_CTX_sess_connect`(), `SSL_CTX_sess_connect_good`(), `SSL_CTX_sess_accept`(), `SSL_CTX_sess_accept_good`(), `SSL_CTX_sess_hits`(), `SSL_CTX_sess_misses`(), and `SSL_CTX_sess_timeouts`() first appeared in SSLeay 0.5.2. `SSL_CTX_sess_cb_hits`() first appeared in SSLeay 0.6.0. `SSL_CTX_sess_connect_renegotiate`(), `SSL_CTX_sess_accept_renegotiate`(), and `SSL_CTX_sess_cache_full`() first appeared in SSLeay 0.9.0. All these functions have been available since OpenBSD 2.4.

June 8, 2025 | Debian