dns_cache_del_nonexp configuration option is introduced: it allows deletion of non...

when the cache becomes full. Disabled by default.

diff --git a/cfg.lex b/cfg.lex
index 3a64c05..8eff204 100644 (file)
--- a/cfg.lex
+++ b/cfg.lex
@@ -251,6 +251,7 @@ DNS_CACHE_MIN_TTL   dns_cache_min_ttl
 DNS_CACHE_MAX_TTL      dns_cache_max_ttl
 DNS_CACHE_MEM          dns_cache_mem
 DNS_CACHE_GC_INT       dns_cache_gc_interval
+DNS_CACHE_DEL_NONEXP   dns_cache_del_nonexp|dns_cache_delete_nonexpired
 /* blacklist */
 USE_DST_BLST           use_dst_blacklist
 DST_BLST_MEM           dst_blacklist_mem
@@ -496,6 +497,8 @@ EAT_ABLE    [\ \t\b\r]
                                                                return DNS_CACHE_MEM; }
 <INITIAL>{DNS_CACHE_GC_INT}    { count(); yylval.strval=yytext;
                                                                return DNS_CACHE_GC_INT; }
+<INITIAL>{DNS_CACHE_DEL_NONEXP}        { count(); yylval.strval=yytext;
+                                                               return DNS_CACHE_DEL_NONEXP; }
 <INITIAL>{USE_DST_BLST}        { count(); yylval.strval=yytext;
                                                                return USE_DST_BLST; }
 <INITIAL>{DST_BLST_MEM}        { count(); yylval.strval=yytext;

diff --git a/cfg.y b/cfg.y
index 833a766..9958356 100644 (file)
--- a/cfg.y
+++ b/cfg.y
@@ -290,6 +290,7 @@ static struct socket_id* mk_listen_id(char*, int, int);
 %token DNS_CACHE_MAX_TTL
 %token DNS_CACHE_MEM
 %token DNS_CACHE_GC_INT
+%token DNS_CACHE_DEL_NONEXP
 /*blacklist*/
 %token USE_DST_BLST
 %token DST_BLST_MEM
@@ -617,6 +618,8 @@ assign_stm:
        | DNS_CACHE_MEM error { yyerror("boolean value expected"); }
        | DNS_CACHE_GC_INT EQUAL NUMBER   { IF_DNS_CACHE(dns_timer_interval=$3); }
        | DNS_CACHE_GC_INT error { yyerror("boolean value expected"); }
+       | DNS_CACHE_DEL_NONEXP EQUAL NUMBER   { IF_DNS_CACHE(dns_cache_del_nonexp=$3); }
+       | DNS_CACHE_DEL_NONEXP error { yyerror("boolean value expected"); }
        | USE_DST_BLST EQUAL NUMBER   { IF_DST_BLACKLIST(use_dst_blacklist=$3); }
        | USE_DST_BLST error { yyerror("boolean value expected"); }
        | DST_BLST_MEM EQUAL NUMBER   { IF_DST_BLACKLIST(blst_max_mem=$3); }

diff --git a/dns_cache.c b/dns_cache.c
index 808f05a..e8d4e95 100644 (file)
--- a/dns_cache.c
+++ b/dns_cache.c
@@ -38,6 +38,7 @@
  *  2008-07-25  various rpc commands to manipulate the content
  *             of the cache (Miklos)
  *  2007-07-30  DNS cache measurements added (Gergo)
+ *  2007-08-17  dns_cache_del_nonexp config option is introduced (Miklos)
  */
 
 #ifdef USE_DNS_CACHE
@@ -98,6 +99,7 @@ unsigned int dns_timer_interval=DEFAULT_DNS_TIMER_INTERVAL; /* in s */
 int dns_flags=0; /* default flags used for the  dns_*resolvehost
                     (compatibility wrappers) */
 int dns_srv_lb=0; /* off by default */
+int dns_cache_del_nonexp=0; /* delete only expired entries by default */
 
 #ifdef USE_DNS_CACHE_STATS
 struct t_dns_cache_stats* dns_cache_stats=0;
@@ -717,7 +719,7 @@ inline static int dns_cache_add(struct dns_hash_entry* e)
 #endif
                LOG(L_WARN, "WARNING: dns_cache_add: cache full, trying to free...\n");
                /* free ~ 12% of the cache */
-               dns_cache_free_mem(*dns_cache_mem_used/16*14, 1);
+               dns_cache_free_mem(*dns_cache_mem_used/16*14, !dns_cache_del_nonexp);
                if ((*dns_cache_mem_used+e->total_size)>=dns_cache_max_mem){
                        LOG(L_ERR, "ERROR: dns_cache_add: max. cache mem size exceeded\n");
                        return -1;
@@ -757,7 +759,7 @@ inline static int dns_cache_add_unsafe(struct dns_hash_entry* e)
                LOG(L_WARN, "WARNING: dns_cache_add: cache full, trying to free...\n");
                /* free ~ 12% of the cache */
                UNLOCK_DNS_HASH();
-               dns_cache_free_mem(*dns_cache_mem_used/16*14, 1);
+               dns_cache_free_mem(*dns_cache_mem_used/16*14, !dns_cache_del_nonexp);
                LOCK_DNS_HASH();
                if ((*dns_cache_mem_used+e->total_size)>=dns_cache_max_mem){
                        LOG(L_ERR, "ERROR: dns_cache_add: max. cache mem size exceeded\n");

diff --git a/doc/dns.txt b/doc/dns.txt
index 472e0e6..9206445 100644 (file)
--- a/doc/dns.txt
+++ b/doc/dns.txt
@@ -242,6 +242,12 @@ DNS Cache and Failover Config Variables
    dns_cache_gc_interval = how often (in s) the dns cache will be garbage 
       collected.
       Default:  120 s.
+      
+   dns_cache_del_nonexp = yes | no or
+   dns_cache_delete_nonexpired = yes | no - allow deletion of non-expired
+      records from the cache when there is no more space left for new
+      ones. The last-recently used entries are deleted first.
+      Default: no
 
 
 DNS Cache Compile Options

diff --git a/globals.h b/globals.h
index 5079bf6..e8cf224 100644 (file)
--- a/globals.h
+++ b/globals.h
@@ -206,6 +206,7 @@ extern unsigned int dns_timer_interval; /* gc timer interval in s */
 extern int dns_flags; /* default flags used for the  dns_*resolvehost
                     (compatibility wrappers) */
 extern int dns_srv_lb; /* default SRV LB support value */
+extern int dns_cache_del_nonexp; /* delete non-expired values from the cache when it is full */
 
 #ifdef USE_DNS_CACHE_STATS
 struct t_dns_cache_stats{