postfix-2.2-20040721

postfix/HISTORY

@@ -9567,6 +9567,13 @@ Apologies for any names omitted.
 	test the effects of collisions in the time or in name space
 	domains. File:  global/scache.c.
 
+20040721
+
+	Feature: the session cache server now logs cache hit and
+	miss statistics every $session_cache_status_update_time
+	seconds (default: 600s), as well as upon process exit.
+	File:  scache/scache.c.
+
 Open problems:
 
 	Low: update events.c so that 1-second timer requests do

postfix/RELEASE_NOTES

@@ -7,6 +7,14 @@ snapshot release).  Patches are issued for the official release
 and change the patchlevel and the release date. Patches are never
 issued for snapshot releases.
 
+Major changes with snapshot Postfix-2.2-20040721
+================================================
+
+The session cache manager now logs cache hit and miss statistics
+every $session_cache_status_update_time seconds (default: 600s).
+It reports the hit and miss rates for lookups by domain, as well
+as for lookups by network address.
+
 Incompatible changes with snapshot Postfix-2.2-20040720
 =======================================================
 
@@ -18,7 +26,7 @@ Major changes with snapshot Postfix-2.2-20040720
 Selective SMTP session caching. Instead of disconnecting immediately
 after a mail transaction, the SMTP client can save the open session
 to a session cache daemon, so that any SMTP client process can use
-the same session for another mail transaction.
+that session for another mail transaction.
 
 This feature introduces the scache (session cache) server, which
 is added to your master.cf file when you upgrade Postfix.
@@ -69,7 +77,8 @@ specified.
 Limitations:
 
 - SMTP session caching does not work with TLS (the necessary support
-for object passivation and re-activation does not exist).
+for object passivation and re-activation does not exist without
+closing the connection).
 
 - SMTP session caching assumes that SASL credentials are valid for
 all hostnames or domain names that map onto the same IP address

postfix/html/postconf.5.html

@@ -5038,6 +5038,16 @@ The default time unit is s (seconds).
 maintains a limited pool of cached sessions.  </p>
 
 
+</DD>
+
+<DT><b><a name="session_cache_status_update_time">session_cache_status_update_time</a>
+(default: 600s)</b></DT><DD>
+
+<p> How frequently the <a href="scache.8.html">scache(8)</a> server logs usage statistics with
+session cache hit and miss rates for logical destinations and for
+physical endpoints. </p>
+
+
 </DD>
 
 <DT><b><a name="session_cache_ttl_limit">session_cache_ttl_limit</a>

postfix/html/scache.8.html

@@ -98,6 +98,12 @@ SCACHE(8)                                               SCACHE(8)
               The maximal time-to-live  value  that  the  session
               cache server allows.
 
+       <b>session_cache_status_update_time (600s)</b>
+              How  frequently  the  <a href="scache.8.html">scache(8)</a>  server  logs usage
+              statistics with session cache hit  and  miss  rates
+              for  logical  destinations  and  for  physical end-
+              points.
+
 <b>MISCELLANEOUS CONTROLS</b>
        <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
               The default location of  the  Postfix  main.cf  and

postfix/html/smtp.8.html

@@ -67,8 +67,9 @@ SMTP(8)                                                   SMTP(8)
 
 <b>BUGS</b>
        SMTP session caching does not work with TLS. The necessary
-       support for object passivation and re-activation does  not
-       exist.
+       support for TLS object passivation and re-activation  does
+       not  exist  without closing the session, which defeats the
+       purpose.
 
        SMTP session caching assumes  that  SASL  credentials  are
        valid  for  all  destinations  that  map  onto the same IP

postfix/man/man5/postconf.5

@@ -2639,6 +2639,10 @@ The default time unit is s (seconds).
 .SH session_cache_service (default: scache)
 The name of the scache(8) session cache service.  This service
 maintains a limited pool of cached sessions.
+.SH session_cache_status_update_time (default: 600s)
+How frequently the scache(8) server logs usage statistics with
+session cache hit and miss rates for logical destinations and for
+physical endpoints.
 .SH session_cache_ttl_limit (default: 2s)
 The maximal time-to-live value that the session cache server
 allows. Requests that specify a larger TTL will be stored with the

postfix/man/man8/scache.8

@@ -100,6 +100,10 @@ postconf(5) for more details including examples.
 .IP "\fBsession_cache_ttl_limit (2s)\fR"
 The maximal time-to-live value that the session cache server
 allows.
+.IP "\fBsession_cache_status_update_time (600s)\fR"
+How frequently the scache(8) server logs usage statistics with
+session cache hit and miss rates for logical destinations and for
+physical endpoints.
 .SH "MISCELLANEOUS CONTROLS"
 .na
 .nf

postfix/man/man8/smtp.8

@@ -71,8 +71,8 @@ other trouble.
 .ad
 .fi
 SMTP session caching does not work with TLS. The necessary
-support for object passivation and re-activation does not
-exist.
+support for TLS object passivation and re-activation does not
+exist without closing the session, which defeats the purpose.
 
 SMTP session caching assumes that SASL credentials are valid for
 all destinations that map onto the same IP address and TCP port.

postfix/proto/postconf.proto

@@ -6928,3 +6928,9 @@ allows. Requests that specify a larger TTL will be stored with the
 maximum allowed TTL. The purpose of this additional control is to
 protect the infrastructure against careless people. The cache TTL
 is already bounded by $max_idle.  </p>
+
+%PARAM session_cache_status_update_time 600s
+
+<p> How frequently the scache(8) server logs usage statistics with
+session cache hit and miss rates for logical destinations and for
+physical endpoints. </p>

postfix/src/global/mail_params.h

@@ -1799,6 +1799,10 @@ extern char *var_scache_service;
 #define DEF_SCACHE_TTL_LIM		"2s"
 extern int var_scache_ttl_lim;
 
+#define VAR_SCACHE_STAT_TIME		"session_cache_status_update_time"
+#define DEF_SCACHE_STAT_TIME		"600s"
+extern int var_scache_stat_time;
+
  /*
   * Address verification service.
   */

postfix/src/global/mail_version.h

@@ -20,7 +20,7 @@
   * Patches change the patchlevel and the release date. Snapshots change the
   * release date only.
   */
-#define MAIL_RELEASE_DATE	"20040720"
+#define MAIL_RELEASE_DATE	"20040721"
 #define MAIL_VERSION_NUMBER	"2.2"
 
 #define VAR_MAIL_VERSION	"mail_version"

postfix/src/global/scache.c

@@ -43,7 +43,7 @@
 /*	The code maintains two types of association: a) physical
 /*	endpoint to file descriptor, and b) logical endpoint
 /*	to physical endpoint. Physical endpoints are stored and
-/*	look up under their low-level session details such as
+/*	looked up under their low-level session details such as
 /*	numerical addresses, while logical endpoints are stored
 /*	and looked up by the domain name that humans use. One logical
 /*	endpoint can refer to multiple physical endpoints, one
@@ -153,8 +153,8 @@
   * Driver program for cache regression tests. Although all variants are
   * relatively simple to verify by hand for single session storage, more
   * sophisticated instrumentation is needed to demonstrate that the
-  * multi-sessin cache manager properly handles collisions in the time domain
-  * and in the various name space domains.
+  * multi-session cache manager properly handles collisions in the time
+  * domain and in all the name space domains.
   */
 static SCACHE *scache;
 static VSTRING *endp_prop;

postfix/src/global/scache_clnt.c

@@ -23,9 +23,6 @@
 /*	Idle time after which the client disconnects.
 /* .IP ttl_limit
 /*	Upper bound on the time that a connection is allowed to persist.
-/* .IP endp_ttl
-/*	How long the session should be cached.  When information
-/*	expires it is purged automatically.
 /* DIAGNOSTICS
 /*	Fatal error: memory allocation problem;
 /*	panic: internal consistency failure.

postfix/src/global/scache_multi.c

@@ -59,8 +59,8 @@
   * destination hash table entry.
   * 
   * Likewise, each endpoint has an entry in the endpoint hash table, and each
-  * endpoint->session binding is kept in a circular list under its hash table
-  * entry.
+  * endpoint->session binding is kept in a circular list under its endpoint
+  * hash table entry.
   * 
   * We do not attempt to limit the number of destination or endpoint entries,
   * nor do we attempt to limit the number of sessions. Doing so would require

postfix/src/scache/scache.c

@@ -84,6 +84,10 @@
 /* .IP "\fBsession_cache_ttl_limit (2s)\fR"
 /*	The maximal time-to-live value that the session cache server
 /*	allows.
+/* .IP "\fBsession_cache_status_update_time (600s)\fR"
+/*	How frequently the scache(8) server logs usage statistics with
+/*	session cache hit and miss rates for logical destinations and for
+/*	physical endpoints.
 /* MISCELLANEOUS CONTROLS
 /* .ad
 /* .fi
@@ -129,6 +133,7 @@
 /* System library. */
 
 #include <sys_defs.h>
+#include <time.h>
 
 /* Utility library. */
 
@@ -136,6 +141,7 @@
 #include <iostuff.h>
 #include <htable.h>
 #include <ring.h>
+#include <events.h>
 
 /* Global library. */
 
@@ -154,6 +160,7 @@
   * Tunable parameters.
   */
 int     var_scache_ttl_lim;
+int     var_scache_stat_time;
 
  /*
   * Request parameters.
@@ -169,6 +176,15 @@ static VSTRING *scache_endp_prop;
   */
 static SCACHE *scache;
 
+ /*
+  * Statistics.
+  */
+static int scache_dest_hits;
+static int scache_dest_miss;
+static int scache_endp_hits;
+static int scache_endp_miss;
+time_t  scache_start_time;
+
  /*
   * Silly little macros.
   */
@@ -235,6 +251,7 @@ static void scache_find_endp_service(VSTREAM *client_stream)
 		   ATTR_TYPE_NUM, MAIL_ATTR_STATUS, SCACHE_STAT_FAIL,
 		   ATTR_TYPE_STR, MAIL_ATTR_PROP, "",
 		   ATTR_TYPE_END);
+	scache_endp_miss++;
 	return;
     } else {
 	attr_print(client_stream, ATTR_FLAG_NONE,
@@ -246,11 +263,12 @@ static void scache_find_endp_service(VSTREAM *client_stream)
 	    msg_warn("%s: cannot send file descriptor: %m", myname);
 	if (close(fd) < 0)
 	    msg_warn("close(%d): %m", fd);
+	scache_endp_hits++;
 	return;
     }
 }
 
-/* scache_save_dest_service - protocol to save destiation->endpoint binding */
+/* scache_save_dest_service - protocol to save destination->endpoint binding */
 
 static void scache_save_dest_service(VSTREAM *client_stream)
 {
@@ -308,6 +326,7 @@ static void scache_find_dest_service(VSTREAM *client_stream)
 		   ATTR_TYPE_STR, MAIL_ATTR_PROP, "",
 		   ATTR_TYPE_STR, MAIL_ATTR_PROP, "",
 		   ATTR_TYPE_END);
+	scache_dest_miss++;
 	return;
     } else {
 	attr_print(client_stream, ATTR_FLAG_NONE,
@@ -320,6 +339,7 @@ static void scache_find_dest_service(VSTREAM *client_stream)
 	    msg_warn("%s: cannot send file descriptor: %m", myname);
 	if (close(fd) < 0)
 	    msg_warn("close(%d): %m", fd);
+	scache_dest_hits++;
 	return;
     }
 }
@@ -364,6 +384,40 @@ static void scache_service(VSTREAM *client_stream, char *unused_service,
     vstream_fflush(client_stream);
 }
 
+/* scache_status_dump - log and reset cache statistics */
+
+static void scache_status_dump(char *unused_name, char **unused_argv)
+{
+    if (scache_dest_hits || scache_dest_miss
+	|| scache_endp_hits || scache_endp_miss)
+	msg_info("statistics: start interval %.15s",
+		 ctime(&scache_start_time) + 4);
+
+    if (scache_dest_hits || scache_dest_miss) {
+	msg_info("statistics: domain lookup hits=%d miss=%d success=%d%%",
+		 scache_dest_hits, scache_dest_miss,
+		 scache_dest_hits * 100
+		 / (scache_dest_hits + scache_dest_miss));
+	scache_dest_hits = scache_dest_miss = 0;
+    }
+    if (scache_endp_hits || scache_endp_miss) {
+	msg_info("statistics: address lookup hits=%d miss=%d success=%d%%",
+		 scache_endp_hits, scache_endp_miss,
+		 scache_endp_hits * 100
+		 / (scache_endp_hits + scache_endp_miss));
+	scache_endp_hits = scache_endp_miss = 0;
+    }
+    scache_start_time = event_time();
+}
+
+/* scache_status_update - log and reset cache statistics periodically */
+
+static void scache_status_update(int unused_event, char *context)
+{
+    scache_status_dump((char *) 0, (char **) 0);
+    event_request_timer(scache_status_update, context, var_scache_stat_time);
+}
+
 /* post_jail_init - initialization after privilege drop */
 
 static void post_jail_init(char *unused_name, char **unused_argv)
@@ -388,6 +442,12 @@ static void post_jail_init(char *unused_name, char **unused_argv)
      * connected for $idle_limit time units.
      */
     var_use_limit = 0;
+
+    /*
+     * Dump and reset cache statistics every so often.
+     */
+    event_request_timer(scache_status_update, (char *) 0, var_scache_stat_time);
+    scache_start_time = event_time();
 }
 
 /* main - pass control to the multi-threaded skeleton */
@@ -396,12 +456,14 @@ int     main(int argc, char **argv)
 {
     static CONFIG_TIME_TABLE time_table[] = {
 	VAR_SCACHE_TTL_LIM, DEF_SCACHE_TTL_LIM, &var_scache_ttl_lim, 1, 0,
+	VAR_SCACHE_STAT_TIME, DEF_SCACHE_STAT_TIME, &var_scache_stat_time, 1, 0,
 	0,
     };
 
     multi_server_main(argc, argv, scache_service,
 		      MAIL_SERVER_TIME_TABLE, time_table,
 		      MAIL_SERVER_POST_INIT, post_jail_init,
+		      MAIL_SERVER_EXIT, scache_status_dump,
 		      MAIL_SERVER_SOLITARY,
 		      0);
 }

postfix/src/smtp/smtp.c

@@ -57,8 +57,8 @@
 /*	other trouble.
 /* BUGS
 /*	SMTP session caching does not work with TLS. The necessary
-/*      support for object passivation and re-activation does not
-/*	exist.
+/*	support for TLS object passivation and re-activation does not
+/*	exist without closing the session, which defeats the purpose.
 /*
 /*	SMTP session caching assumes that SASL credentials are valid for
 /*	all destinations that map onto the same IP address and TCP port.

postfix/src/smtp/smtp_connect.c

@@ -582,6 +582,7 @@ int     smtp_connect(SMTP_STATE *state)
 	    if (++addr_count == var_smtp_mxaddr_limit)
 		next = 0;
 	    if ((sess_flags & SMTP_SESS_FLAG_CACHE) == 0
+		|| addr->pref == domain_best_pref
 		|| (session = smtp_reuse_addr(state, addr, port)) == 0)
 		session = smtp_connect_addr(dest, addr, port, why, sess_flags);
 	    if ((state->session = session) != 0) {