id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
621	Could not allocate new session in SSL session shared cache	Johannes Ziemke		"Hi,

I'm using nginx as reverse proxy in front of haproxy. I'm using this ssl_session_cache config:


{{{
ssl_session_cache   shared:SSL:10m;
ssl_session_timeout 512m;
}}}

Now I get from time to time such errors in the log:

{{{
2014-09-03T09:51:34+00:00 hostname nginx: 2014/09/03 09:51:34 [alert] 27#0: *144835271 could not allocate new session in SSL session shared cache ""SSL"" while SSL handshaking, client: a.b.c.d, server: 0.0.0.0:443
}}}

Unfortunately that error doesn't say much. Looking at the code shows that it probably failed to allocate via ngx_slab_alloc_locked():

https://github.com/nginx/nginx/blob/master/src/event/ngx_event_openssl.c#L2088

I'll try to raise the session cache and see if it helps, but since it's just a cache I would expect only performance differences.

FWIW: The nginx is running in a docker container, to be specific: https://registry.hub.docker.com/u/fish/haproxy/ (Although I've raised the cache setting there already "	defect	closed	major		nginx-core	1.7.x	fixed	ssl		Linux [host] 3.8.0-35-generic #52~precise1-Ubuntu SMP Thu Jan 30 17:24:40 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux	"nginx version: nginx/1.7.1
TLS SNI support enabled
configure arguments: --with-cc-opt='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2' --with-ld-opt='-Wl,-Bsymbolic-functions -Wl,-z,relro' --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-debug --with-pcre-jit --with-ipv6 --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_addition_module --with-http_dav_module --with-http_geoip_module --with-http_gzip_static_module --with-http_image_filter_module --with-http_spdy_module --with-http_sub_module --with-http_xslt_module --with-mail --with-mail_ssl_module --add-module=/build/buildd/nginx-1.7.1/debian/modules/nginx-auth-pam --add-module=/build/buildd/nginx-1.7.1/debian/modules/nginx-dav-ext-module --add-module=/build/buildd/nginx-1.7.1/debian/modules/nginx-echo --add-module=/build/buildd/nginx-1.7.1/debian/modules/nginx-upstream-fair --add-module=/build/buildd/nginx-1.7.1/debian/modules/ngx_http_substitutions_filter_module"