From: Andrew Bartlett <abartlet@samba.org>
Date: Fri, 18 May 2012 12:01:14 +0000 (+1000)
Subject: s3-libads: Use a reducing page size to try and cope with a slow LDAP server
X-Git-Url: http://git.samba.org/?p=ddiss%2Fsamba.git;a=commitdiff_plain;h=0f58ea6c58d78c845aa3fda22c238f126620d226

s3-libads: Use a reducing page size to try and cope with a slow LDAP server

If we cannot get 1000 users downloaded in 15seconds, try with 500, 250
and then 125 users at a time.

Andrew Bartlett
---

diff --git a/source3/include/ads.h b/source3/include/ads.h
index 8a8ce28e530..5d43275b7e8 100644
--- a/source3/include/ads.h
+++ b/source3/include/ads.h
@@ -61,6 +61,7 @@ typedef struct ads_struct {
 		time_t current_time;
 		char *schema_path;
 		char *config_path;
+		int ldap_page_size;
 	} config;
 
 	/* info about the current LDAP connection */
diff --git a/source3/libads/ads_struct.c b/source3/libads/ads_struct.c
index b6c8e995ed4..e2e7df52366 100644
--- a/source3/libads/ads_struct.c
+++ b/source3/libads/ads_struct.c
@@ -149,6 +149,10 @@ ADS_STRUCT *ads_init(const char *realm,
 
 	ads->auth.flags = wrap_flags;
 
+	/* Start with a page size of 1000 when the connection is new,
+	 * we will drop it by half we get a timeout.   */
+	ads->config.ldap_page_size     = 1000;
+
 	return ads;
 }
 
diff --git a/source3/libads/ldap.c b/source3/libads/ldap.c
index 90c645c44ad..e62a4b4137d 100644
--- a/source3/libads/ldap.c
+++ b/source3/libads/ldap.c
@@ -930,11 +930,11 @@ static ADS_STATUS ads_do_paged_search_args(ADS_STRUCT *ads,
 
 	cookie_be = ber_alloc_t(LBER_USE_DER);
 	if (*cookie) {
-		ber_printf(cookie_be, "{iO}", (ber_int_t) 1000, *cookie);
+		ber_printf(cookie_be, "{iO}", (ber_int_t) ads->config.ldap_page_size, *cookie);
 		ber_bvfree(*cookie); /* don't need it from last time */
 		*cookie = NULL;
 	} else {
-		ber_printf(cookie_be, "{io}", (ber_int_t) 1000, "", 0);
+		ber_printf(cookie_be, "{io}", (ber_int_t) ads->config.ldap_page_size, "", 0);
 	}
 	ber_flatten(cookie_be, &cookie_bv);
 	PagedResults.ldctl_oid = CONST_DISCARD(char *, ADS_PAGE_CTL_OID);
diff --git a/source3/libads/ldap_utils.c b/source3/libads/ldap_utils.c
index ab77abdd16b..8865785eb9d 100644
--- a/source3/libads/ldap_utils.c
+++ b/source3/libads/ldap_utils.c
@@ -84,6 +84,13 @@ static ADS_STATUS ads_do_search_retry_internal(ADS_STRUCT *ads, const char *bind
 
 	while (--count) {
 
+		if (NT_STATUS_EQUAL(ads_ntstatus(status), NT_STATUS_IO_TIMEOUT) && ads->config.ldap_page_size >= 250) {
+			int new_page_size = (ads->config.ldap_page_size / 2);
+			DEBUG(1, ("Reducing LDAP page size from %d to %d due to IO_TIMEOUT\n",
+				  ads->config.ldap_page_size, new_page_size));
+			ads->config.ldap_page_size = new_page_size;
+		}
+
 		if (*res) 
 			ads_msgfree(ads, *res);
 		*res = NULL;