I looked around for a while but don't know yet if a corresponding issue
in the HTTPD bug tracker exists. Does anyone know?
On the surface it looks like a memory pool corruption bug to me.
The stack trace posted in https://svn.haxx.se/users/archive-2014-05/0000.shtml points towards an endless loop in apr_pool_cleanup_kill().
The trace ends at APR-util's misc/apr_reslist.c:apr_reslist_cleanup_order_set,
and of the functions this calls only apr_pool_cleanup_kill() contains loops.
I could not do any further debugging since I only had a production setup
to look at, which is stable with the workaround 'LDAPSharedCacheSize 0'.
I also do not have a Windows dev environment and I don't plan on digging
Until the real bug gets found and fixed, I would recommend making the
known workaround the default on Windows. Because the winnt MPM runs a
single process, there is no benefit to a shared memory cache anyway.
+ /* XXX The shared memory cache can cause an endless loop on Windows.
+ * See https://svn.haxx.se/users/archive-2014-05/0000.shtml and
+ * similar reports elsewhere which recommend 'LDAPSharedCacheSize 0'
+ * as a workaround.
+ * Because the winnt MPM uses a single process a shared cache is
+ * not needed anyway so leave it disabled by default. */
+ st->cache_bytes = 0;
st->cache_bytes = 500000;
st->search_cache_ttl = 600000000;
st->search_cache_size = 1024;
st->compare_cache_ttl = 600000000;