Probably ssl_scache problem?

[Prologas]

Hello,

strange log came out from web error log:

[Wed Mar 02 07:16:43.065232 2016] [ssl:warn] [pid 21319:tid 139972619179776] (43)Identifier removed: AH02026: Failed to acquire SSL session cache lock
[Wed Mar 02 07:16:43.065282 2016] [ssl:warn] [pid 21319:tid 139972619179776] (43)Identifier removed: AH02027: Failed to release SSL session cache lock
[Wed Mar 02 07:16:43.135303 2016] [ssl:warn] [pid 21319:tid 139972493301504] (43)Identifier removed: AH02026: Failed to acquire SSL session cache lock
[Wed Mar 02 07:16:43.135329 2016] [ssl:warn] [pid 21319:tid 139972493301504] (43)Identifier removed: AH02027: Failed to release SSL session cache lock
[Wed Mar 02 07:16:43.370244 2016] [ssl:warn] [pid 21319:tid 139972776527616] (43)Identifier removed: AH02026: Failed to acquire SSL session cache lock
[Wed Mar 02 07:16:43.370278 2016] [ssl:warn] [pid 21319:tid 139972776527616] (43)Identifier removed: AH02027: Failed to release SSL session cache lock
[Wed Mar 02 07:16:43.380653 2016] [ssl:warn] [pid 21319:tid 139972545750784] (43)Identifier removed: AH02026: Failed to acquire SSL session cache lock

If we take a look at:

/etc/httpd/conf/extra/httpd-ssl.conf

SSLSessionCache shmcb:/var/log/httpd/ssl_scache(512000)
SSLSessionCacheTimeout 300

but ssl_scache don't exist at this dir. So how it can be locked?

Any ideas to fix this error?

Thanks!

 

[Prologas]

any help will be greatly appreciated!