Make pdb_ldap use a random factor in deciding how long we need to sleep.

This might help avoid killing the ldap server when all 100 smbd processes
reconnect in pulses...

Also, reduces the maximum wait time, as SMB clients will time out after 30
seconds anyway...

Andrew Bartlett

1 files changed, 22 insertions, 7 deletions

diff --git a/source/passdb/pdb_ldap.c b/source/passdb/pdb_ldap.c
index 2eeb96d9b17..741a89da143 100644
--- a/source/passdb/pdb_ldap.c
+++ b/source/passdb/pdb_ldap.c
@@ -74,6 +74,8 @@ struct ldapsam_privates {
 
 	char *bind_dn;
 	char *bind_secret;
+
+	unsigned int num_failures;
 };
 
 #define LDAPSAM_DONT_PING_TIME 10	/* ping only all 10 seconds */
@@ -166,7 +168,7 @@ static int ldapsam_open_connection (struct ldapsam_privates *ldap_state, LDAP **
 	int version;
 	BOOL ldap_v3 = False;
 
-#if defined(LDAP_API_FEATURE_X_OPENLDAP) && (LDAP_API_VERSION > 2000)
+#ifdef HAVE_LDAP_INITIALIZE
 	DEBUG(10, ("ldapsam_open_connection: %s\n", ldap_state->uri));
 	
 	if ((rc = ldap_initialize(ldap_struct, ldap_state->uri)) != LDAP_SUCCESS) {
@@ -409,15 +411,18 @@ static int ldapsam_connect_system(struct ldapsam_privates *ldap_state, LDAP * ld
 		char *ld_error = NULL;
 		ldap_get_option(ldap_state->ldap_struct, LDAP_OPT_ERROR_STRING,
 				&ld_error);
-		DEBUG(0,
+		DEBUG(ldap_state->num_failures ? 2 : 0,
 		      ("failed to bind to server with dn= %s Error: %s\n\t%s\n",
 			       ldap_dn ? ld_error : "(unknown)", ldap_err2string(rc),
 			       ld_error));
 		SAFE_FREE(ld_error);
+		ldap_state->num_failures++;
 		return rc;
 	}
-	
-	DEBUG(2, ("ldap_connect_system: succesful connection to the LDAP server\n"));
+
+	ldap_state->num_failures = 0;
+
+	DEBUG(3, ("ldap_connect_system: succesful connection to the LDAP server\n"));
 	return rc;
 }
 
@@ -499,13 +504,23 @@ static int ldapsam_retry_open(struct ldapsam_privates *ldap_state, int *attempts
 	SMB_ASSERT(ldap_state && attempts);
 		
 	if (*attempts != 0) {
-		/* we retry after 0.5, 2, 4.5, 8, 12.5, 18, 24.5 seconds */
-		msleep((((*attempts)*(*attempts))/2)*1000);
+		unsigned int sleep_time;
+		uint8 rand_byte = 128; /* a reasonable place to start */
+
+		generate_random_buffer(&rand_byte, 1, False);
+
+		sleep_time = (((*attempts)*(*attempts))/2)*rand_byte*2; 
+		/* we retry after (0.5, 1, 2, 3, 4.5, 6) seconds
+		   on average.  
+		 */
+		DEBUG(3, ("Sleeping for %u milliseconds before reconnecting\n", 
+			  sleep_time));
+		msleep(sleep_time);
 	}
 	(*attempts)++;
 
 	if ((rc = ldapsam_open(ldap_state))) {
-		DEBUG(0,("Connection to LDAP Server failed for the %d try!\n",*attempts));
+		DEBUG(1,("Connection to LDAP Server failed for the %d try!\n",*attempts));
 		return rc;
 	}