From 2eaa646655f8f3f4b51d352b007670aff983bb63 Mon Sep 17 00:00:00 2001
From: Eric Covener
Date: Sat, 5 Jul 2014 00:06:15 +0000
Subject: [PATCH] make LDAPConnectionPoolTTL more conservative, use
r->request_time rather than end-of-request time, and only update it after a
round-trip with the LDAP server rather than every time we check back into the
pool.
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1607960 13f79535-47bb-0310-9956-ffa450edef68
---
CHANGES | 3 +++
docs/manual/mod/mod_ldap.xml | 19 ++++++++++++-------
include/ap_mmn.h | 3 ++-
include/util_ldap.h | 1 +
modules/ldap/util_ldap.c | 14 ++++++++++----
5 files changed, 28 insertions(+), 12 deletions(-)
diff --git a/CHANGES b/CHANGES
index ef00d3f091..a0ed7ca99e 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,9 @@
-*- coding: utf-8 -*-
Changes with Apache 2.5.0
+ *) mod_ldap: Be more conservative with the last-used time for
+ LDAPConnectionPoolTTL. PR54587 [Eric Covener]
+
*) mod_deflate: Don't fail when flushing inflated data to the user-agent
and that coincides with the end of stream ("Zlib error flushing inflate
buffer"). PR 56196. [Christoph Fausak ]
diff --git a/docs/manual/mod/mod_ldap.xml b/docs/manual/mod/mod_ldap.xml
index 672c5d69d2..811c18b59e 100644
--- a/docs/manual/mod/mod_ldap.xml
+++ b/docs/manual/mod/mod_ldap.xml
@@ -755,13 +755,18 @@ connection client certificates.
A setting of 0 causes connections to never be saved in the backend
connection pool. The default value of -1, and any other negative value,
- allows connections of any age to be reused.
-
- The timemout is based on when the LDAP connection is returned to the
- pool, not based on the last time I/O has been performed over the backend
- connection. If the information is cached, the apparent idle time can exceed
- the LDAPConnectionPoolTTL.
-
+ allows connections of any age to be reused.
+
+ For performance reasons, the reference time used by this directive is
+ based on when the LDAP connection is returned to the pool, not the time
+ of the last successful I/O with the LDAP server.
+
+ Since 2.4.10, new measures are in place to avoid the reference time
+ from being inflated by cache hits or slow requests. First, the reference
+ time is not updated if no backend LDAP conncetions were needed. Second,
+ the reference time uses the time the HTTP request was received instead
+ of the time the request is completed.
+
This timeout defaults to units of seconds, but accepts
suffixes for milliseconds (ms), minutes (min), and hours (h).
diff --git a/include/ap_mmn.h b/include/ap_mmn.h
index c01fb3461f..eea914c853 100644
--- a/include/ap_mmn.h
+++ b/include/ap_mmn.h
@@ -463,6 +463,7 @@
ap_mpm_register_socket_callback_timeout.
* 20140611.1 (2.5.0-dev) Add ap_proxy_connect_uds().
* 20140627.0 (2.5.0-dev) Revert 20140611.0 change.
+ * 20140627.1 (2.5.0-dev) add last_backend_conn to util_ldap_connection_t
*/
#define MODULE_MAGIC_COOKIE 0x41503235UL /* "AP25" */
@@ -470,7 +471,7 @@
#ifndef MODULE_MAGIC_NUMBER_MAJOR
#define MODULE_MAGIC_NUMBER_MAJOR 20140627
#endif
-#define MODULE_MAGIC_NUMBER_MINOR 0 /* 0...n */
+#define MODULE_MAGIC_NUMBER_MINOR 1 /* 0...n */
/**
* Determine if the server's current MODULE_MAGIC_NUMBER is at least a
diff --git a/include/util_ldap.h b/include/util_ldap.h
index 1dc0ee2bd1..aa79fc3065 100644
--- a/include/util_ldap.h
+++ b/include/util_ldap.h
@@ -135,6 +135,7 @@ typedef struct util_ldap_connection_t {
apr_pool_t *rebind_pool; /* frequently cleared pool for rebind data */
int must_rebind; /* The connection was last bound with other then binddn/bindpw */
request_rec *r; /* request_rec used to find this util_ldap_connection_t */
+ apr_time_t last_backend_conn; /* the approximate time of the last backend LDAP requst */
} util_ldap_connection_t;
typedef struct util_ldap_config_t {
diff --git a/modules/ldap/util_ldap.c b/modules/ldap/util_ldap.c
index 750e6a7259..38c9b86493 100644
--- a/modules/ldap/util_ldap.c
+++ b/modules/ldap/util_ldap.c
@@ -524,6 +524,7 @@ static int uldap_simple_bind(util_ldap_connection_t *ldc, char *binddn,
return uldap_ld_errno(ldc);
}
else {
+ ldc->last_backend_conn = ldc->r->request_time;
ap_log_rerror(APLOG_MARK, APLOG_TRACE5, 0, ldc->r, "LDC %pp bind", ldc);
}
return rc;
@@ -730,10 +731,10 @@ static util_ldap_connection_t *
&& !compare_client_certs(dc->client_certs, l->client_certs))
{
if (st->connection_pool_ttl > 0) {
- if (l->bound && (now - l->freed) > st->connection_pool_ttl) {
+ if (l->bound && (now - l->last_backend_conn) > st->connection_pool_ttl) {
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Removing LDAP connection last used %" APR_TIME_T_FMT " seconds ago",
- (now - l->freed) / APR_USEC_PER_SEC);
+ (now - l->last_backend_conn) / APR_USEC_PER_SEC);
l->r = r;
uldap_connection_unbind(l);
/* Go ahead (by falling through) and use it, so we don't create more just to unbind some other old ones */
@@ -768,10 +769,10 @@ static util_ldap_connection_t *
!compare_client_certs(dc->client_certs, l->client_certs))
{
if (st->connection_pool_ttl > 0) {
- if (l->bound && (now - l->freed) > st->connection_pool_ttl) {
+ if (l->bound && (now - l->last_backend_conn) > st->connection_pool_ttl) {
ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
"Removing LDAP connection last used %" APR_TIME_T_FMT " seconds ago",
- (now - l->freed) / APR_USEC_PER_SEC);
+ (now - l->last_backend_conn) / APR_USEC_PER_SEC);
l->r = r;
uldap_connection_unbind(l);
/* Go ahead (by falling through) and use it, so we don't create more just to unbind some other old ones */
@@ -995,6 +996,7 @@ start_over:
return result;
}
+ ldc->last_backend_conn = r->request_time;
entry = ldap_first_entry(ldc->ldap, res);
searchdn = ldap_get_dn(ldc->ldap, entry);
@@ -1146,6 +1148,7 @@ start_over:
goto start_over;
}
+ ldc->last_backend_conn = r->request_time;
ldc->reason = "Comparison complete";
if ((LDAP_COMPARE_TRUE == result) ||
(LDAP_COMPARE_FALSE == result) ||
@@ -1271,6 +1274,7 @@ start_over:
return res;
}
+ ldc->last_backend_conn = r->request_time;
entry = ldap_first_entry(ldc->ldap, sga_res);
/*
@@ -1753,6 +1757,7 @@ start_over:
* We should have found exactly one entry; to find a different
* number is an error.
*/
+ ldc->last_backend_conn = r->request_time;
count = ldap_count_entries(ldc->ldap, res);
if (count != 1)
{
@@ -2013,6 +2018,7 @@ start_over:
* We should have found exactly one entry; to find a different
* number is an error.
*/
+ ldc->last_backend_conn = r->request_time;
count = ldap_count_entries(ldc->ldap, res);
if (count != 1)
{
--
2.40.0