From f217d9e96dc8de88916e8ca0b93dd9a7500bbbc3 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Dan=20Vr=C3=A1til?= <dvratil@redhat.com>

Date: Tue, 6 May 2014 16:38:17 +0200

Subject: [PATCH 5/7] Fix PostgreSQL start when postmaster.pid is not removed

 after non-clean shutdown

When PostgreSQL is not terminated nicely, a pidfile is left behind in db_data,

which will prevent pg_ctl from starting a new PostgreSQL server.

We check for postmaster.pid file and verify that postgres server with PID

specified in the pidfile is not running anymore, then delete the pidfile to

allow pg_ctl to start a new server. If the postgres server is still running

(possibly after Akonadi server crash), we try to connect to it right away.

BUG: 286826

FIXED-IN: 1.12.2

---

 server/src/storage/dbconfigpostgresql.cpp | 37 +++++++++++++++++++++++++++++++

 1 file changed, 37 insertions(+)

diff --git a/server/src/storage/dbconfigpostgresql.cpp b/server/src/storage/dbconfigpostgresql.cpp

index 66e4605..7b61819 100644

--- a/server/src/storage/dbconfigpostgresql.cpp

+++ b/server/src/storage/dbconfigpostgresql.cpp

@@ -166,6 +166,43 @@ void DbConfigPostgresql::startInternalServer()

     QDir().mkpath( socketDir );

   }

+// TODO Windows support

+#ifndef Q_WS_WIN

+  // If postmaster.pid exists, check whether the postgres process still exists too,

+  // because normally we shouldn't be able to get this far if Akonadi is already

+  // running. If postgres is not running, then the pidfile was left after a system

+  // crash or something similar and we can remove it (otherwise pg_ctl won't start)

+  QFile postmaster( QString::fromLatin1( "%1/postmaster.pid" ).arg( mPgData ) );

+  if ( postmaster.exists() && postmaster.open( QIODevice::ReadOnly ) ) {

+    qDebug() << "Found a postmaster.pid pidfile, checking whether the server is still running...";

+    QByteArray pid = postmaster.readLine();

+    // Remvoe newline character

+    pid.truncate(pid.size() - 1);

+    QFile proc( QString::fromLatin1( "/proc/" + pid + "/stat" ) );

+    // Check whether the process with the PID from pidfile still exists and whether

+    // it's actually still postgres or, whether the PID has been recycled in the

+    // meanwhile.

+    if ( proc.open( QIODevice::ReadOnly ) ) {

+      const QByteArray stat = proc.readAll();

+      const QList<QByteArray> stats = stat.split( ' ' );

+      if ( stats.count() > 1 ) {

+        // Make sure the PID actually belongs to postgres process

+        if ( stats[1] == "(postgres)" ) {

+          // Yup, our PostgreSQL is actually running, so pretend we started the server

+          // and try to connect to it

+          qWarning() << "PostgreSQL for Akonadi is already running, trying to connect to it.";

+          return;

+        }

+      }

+      proc.close();

+    }

+

+    qDebug() << "No postgres process with specified PID is running. Removing the pidfile and starting a new Postgres instance...";

+    postmaster.close();

+    postmaster.remove();

+  }

+#endif

+

   if ( !QFile::exists( QString::fromLatin1( "%1/PG_VERSION" ).arg( mPgData ) ) ) {

     // postgres data directory not initialized yet, so call initdb on it

-- 

1.9.3