ITS#6176

CHANGES

@@ -28,6 +28,7 @@ OpenLDAP 2.4.17 Engineering
 	Fixed slapd sockets usage on windows (ITS#6039)
 	Fixed slapd some abandon and cancel race conditions (ITS#6104)
 	Fixed slapd tls context after changes (ITS#6135)
+	Fixed slapd-bdb/hdb adjust dncachesize if too low (ITS#6176)
 	Fixed slapd-hdb freeing of already freed entries (ITS#6074)
 	Fixed slapd-hdb entryinfo cleanup (ITS#6088)
 	Fixed slapd-hdb dncache lockups (ITS#6095)

doc/man/man5/slapd-bdb.5

@@ -147,7 +147,10 @@ will return a different result.
 .BI dncachesize \ <integer>
 Specify the maximum number of DNs in the in-memory DN cache. The
 default is twice the \fBcachesize\fP. Ideally this cache should be
-large enough to contain the DNs of every entry in the database.
+large enough to contain the DNs of every entry in the database. If
+set to a smaller value than the \fBcachesize\fP it will be silently
+increased to equal the \fBcachesize\fP.
+
 It should be noted that the \fBDN cache\fP is allowed to temporarily
 grow beyond the configured size. It does this if many entries are 
 locked when it tries to do a purge, because that means they're

servers/slapd/back-bdb/init.c

@@ -374,6 +374,11 @@ shm_retry:
 		bdb->bi_cache.c_eimax = bdb->bi_cache.c_maxsize * 2;
 	}
 
+	/* dncache must be >= entrycache */
+	if ( bdb->bi_cache.c_eimax < bdb->bi_cache.c_maxsize ) {
+		bdb->bi_cache.c_eimax = bdb->bi_cache.c_maxsize;
+	}
+
 	if ( bdb->bi_idl_cache_max_size ) {
 		bdb->bi_idl_tree = NULL;
 		bdb->bi_idl_cache_size = 0;