Session GC fix: save session.modified field as UTC so our comparisons work.

Had to tweak statusnet.ini to remove the DB_DATAOBJECT_MYSQLTIMESTAMP bitfield constant on session.modified; while it sounds like a useful and legit setting, it actually just means that DB_DataObject silently fails to pass through any attempts to explicitly set the value. As a result, MySQL does its default behavior which is to insert the current *LOCAL* time, which is useless.
This was leading to early GC west of GMT, or late GC east of it. Early GC could at worst destroy all live sessions (whoever's session *triggered* GC is fine, as the session then gets saved right back.)

diff --git a/classes/Session.php b/classes/Session.php
index 166b89815a85bd42cee95381cc8b7f5484f16633..b9daf364dba58e7b5e7881cef4ed2ffab214595a 100644 (file)
--- a/classes/Session.php
+++ b/classes/Session.php
@@ -87,6 +87,7 @@ class Session extends Memcached_DataObject
             $session->id           = $id;
             $session->session_data = $session_data;
             $session->created      = common_sql_now();
+            $session->modified     = common_sql_now();
 
             $result = $session->insert();
 
@@ -108,6 +109,7 @@ class Session extends Memcached_DataObject
                 $orig = clone($session);
 
                 $session->session_data = $session_data;
+                $session->modified     = common_sql_now();
 
                 $result = $session->update($orig);
 

diff --git a/classes/statusnet.ini b/classes/statusnet.ini
index ef631e28d376668940e579f05cc0a300ad14cab4..29fde93b5d497a347e9e005eb15b86c3607ea81d 100644 (file)
--- a/classes/statusnet.ini
+++ b/classes/statusnet.ini
@@ -513,7 +513,20 @@ profile_id = K
 id = 130
 session_data = 34
 created = 142
-modified = 384
+modified = 142
+; Warning: using DB_DATAOBJECT_MYSQLTIMESTAMP (256) causes DB_DataObject
+; to SILENTLY REMOVE ATTEMPTS TO SET THIS FIELD DIRECTLY, which is pretty
+; bad because the default behavior for auto-updated TIMESTAMP fields is
+; to use local time. Local time can't be compared to UTC in any useful
+; way, so doing that breaks session GC.
+;
+; Instead we'll use the plain datetime settings so it'll actually save the
+; UTC value we provide when updating.
+;
+; Long-term fix: punch MySQL in the face until it understands that local
+; time is a tool of the cyber-devil.
+;
+;modified = 384
 
 [session__keys]
 id = K