A leak of 148 bytes happens everytime the function ssl_scache_dbm_retrieve() calls d2i_SSL_SESSION() because the buffer pointed to by ucpData, which is locally malloced in ssl_scache_dbm_retrieve is never freed. This really adds up over time. Also, since d2i_SSL_SESSION() changes the address pointed to by ucpData we need to save off a copy of the address in a temporary pointer so that we can actually free it. There are other source files that do the same thing but I want to get input on this one which is causing me problems. Attached is a patch file.
Created attachment 9649 [details] Patch containing fix for memory leak in ssl_scache_dbm_retrieve.
PatchAvailable
*** Bug 21376 has been marked as a duplicate of this bug. ***
it seems we're affected by this bug too. we are running Apache/2.0.52 (Win32) mod_ssl/2.0.52 OpenSSL/0.9.7d on a NT box. apache is acting as SSL frontend and reverse proxy for a bunch of applications. the child process is starting at around 14M, rapidly growing to 30M and then constantly leaking memory. after 30k accesses, memory usage is at around 50M. as workaround, we set MaxRequestsPerChild 30000.
Switching to shmcb is the best workaround.
Thanks. Somehow I was convinced that only dbm would work for SSLSessionCache on win32 platforms. This was the case in 1.3, IIRC.
use of shmcb prevents memory leak as described in comment #4. I would have proposed to make shmcb the default for SSLSessionCache, but this has already been done in HEAD: http://cvs.apache.org/viewcvs.cgi/httpd-2.0/docs/conf/ssl-std.conf.in?r1=1.6&r2=1.7 It would be great to see this backported to APACHE_2_0_BRANCH, eventualy with some update to docs (httpd.apache.org/docs-2.0/mod/mod_ssl.html#sslsessioncache)
*** Bug 34039 has been marked as a duplicate of this bug. ***
See also notes in Bug 25667
Sorry to anyone stuck in an infinite loop, see also Bug 44795 (mixed up bug, two issues, scroll to Michael's comments).
(In reply to comment #10) > Sorry to anyone stuck in an infinite loop, see also Bug 44795 (mixed up bug, > two issues, scroll to Michael's comments). It is actually Bug 44975 intead of 44795.
Fixed in trunk by makeing the the ssl session cache use mod_slotmem*
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