Introduce connection idle timeout.

* NEWS: Updated.
* configure.ac: Version 2.2.90
* doc/vmod-dbrw.3: Document connection idle timeout.
* doc/vmod-dbrw.texi: Likewise.
* src/dbrw.h (dbrw_backend) <sql_idle_timeout>: New method.
(dbrw_config)<idle_timeout>: New member.
(dbrw_connection)<timestamp>: New member.
(sql_idle_timeout): New proto.
* src/mysql.c (vmod_mysql_data) <mysql>: Change storage.
All uses changed.
(s_mysql_idle_timeout): New function.
* src/sql.c (sql_idle_timeout): New function.
(sql_query): Update connection timestamp.
(sql_idle_timeout): New function.
* src/vmod_dbrw.c (dbrw_connection_get): Force disconnect if connection
remained idle for too long. Initialize cfg->idle_timeout.
(vmod_config): New parameter 'timeout='

2 files changed, 29 insertions, 2 deletions

diff --git a/doc/vmod-dbrw.3 b/doc/vmod-dbrw.3
index 139fbab..6f1dba8 100644
--- a/doc/vmod-dbrw.3
+++ b/doc/vmod-dbrw.3
@@ -13,7 +13,7 @@
 .\"
 .\" You should have received a copy of the GNU General Public License
 .\" along with vmod-dbrw.  If not, see <http://www.gnu.org/licenses/>.
-.TH VMOD-DBRW 1 "August 5, 2017" "VMOD-DBRW" "User Reference"
+.TH VMOD-DBRW 1 "January 30, 2018" "VMOD-DBRW" "User Reference"
 .SH NAME
 vmod-dbrw \- Database-driven rewrite rules for Varnish Cache
 .SH SYNOPSIS
@@ -99,6 +99,18 @@ section name is \fBclient\fR.
 Use secure connection to the database server via SSL.  The \fIFILE\fR
 is a full pathname to the certificate authority file.
 .TP
+\fBtimeout\fR=\fIN\fR
+Sets idle timeout for a single connection (seconds).  The connection
+will be closed and opened again if the module is to use it after
+\fIN\fR or more seconds since its last use. Set \fBtimeout=-1\fR to
+disable idle timeout (sessions will remain open until the SQL
+server closes them). Set \fBtimeout=0\fR to close the connection after
+each request (not recommended).
+
+The default depends on the selected SQL backend.  For MySQL, it equals
+the value of the \fBwait_timeout\fR global variable.  For PostgreSQL,
+it is \fB-1\fR.
+.TP
 \fBoptions\fR=\fISTRING\fR
 (\fBPostgres\fR-specific) Connection options.
 .TP
diff --git a/doc/vmod-dbrw.texi b/doc/vmod-dbrw.texi
index 82adda2..40fc84d 100644
--- a/doc/vmod-dbrw.texi
+++ b/doc/vmod-dbrw.texi
@@ -30,7 +30,7 @@ Published by the Free Software Foundation,
 51 Franklin Street, Fifth Floor,
 Boston, MA 02110-1301 USA
 
-Copyright @copyright{} 2013-2017 Sergey Poznyakoff
+Copyright @copyright{} 2013-2018 Sergey Poznyakoff
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -310,6 +310,21 @@ Use secure connection to the database server via SSL.  The
 @var{filename} argument is a full pathname of the certificate
 authority file.
 
+@kwindex timeout
+@cindex timeout, idle, SQL
+@cindex idle timeout, SQL
+@item timeout=@var{n}
+Sets idle timeout for a single connection.  The connection will be
+closed and opened again if the module is to use it after @var{n} or
+more seconds since its last use. Set @samp{timeout=-1} to disable idle
+timeout (session will remain open until the SQL server closes it). Set
+@samp{timeout=0} to close the connection after each request (not
+recommended).
+
+The default depends on the selected SQL backend.  For MySQL, it equals
+the value of the @samp{wait_timeout} global variable.  For PostgreSQL,
+it is @samp{-1}.
+
 @kindex options
 @cindex options, PostgreSQL
 @item options=@var{string}