From what I could figure if I use the forward=redirect option instead of
Running on Ubuntu 16.04 LTS, database and clients run on the same system. I am using the Dec2016 branch, and noticed that the database connections get dropped randomly, but in high frequency. This error occurs irrespective for whether I use mclient, python package (pymonetdb) or the JDBC driver from the site. the default proxy, the frequency reduces drastically, but is still present (if I leave the mclient connection idle for like 5 minutes it will drop - is there an idle time out somewhere ? Also is there a way to force a network connection locally instead of unix socket ? ). Sample of some messages For the default proxy option ===========================
From merovingian.log
rows=cursor.execute("SELECT 'HELLO';"); Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/local/lib/python3.5/dist-packages/pymonetdb/sql/cursors.py",
2016-12-01 10:59:33 MSG merovingian[29445]: target connection is on local UNIX domain socket, passing on filedescriptor instead of proxying Python error due to dropped connection. line 164, in execute block = self.connection.execute(query) File "/usr/local/lib/python3.5/dist-packages/pymonetdb/sql/connections.py", line 133, in execute return self.command('s' + query + ';') File "/usr/local/lib/python3.5/dist-packages/pymonetdb/sql/connections.py", line 138, in command return self.mapi.cmd(command) File "/usr/local/lib/python3.5/dist-packages/pymonetdb/mapi.py", line 208, in cmd self._putblock(operation) File "/usr/local/lib/python3.5/dist-packages/pymonetdb/mapi.py", line 310, in _putblock self._putblock_inet(block) File "/usr/local/lib/python3.5/dist-packages/pymonetdb/mapi.py", line 321, in _putblock_inet self.socket.send(flag) BrokenPipeError: [Errno 32] Broken pipe JDBC Error (I am using PyCharm to execute some SQLs) [08000] Connection to server lost! (mserver still alive?) On the other hand, mclient does not show any error message, tried -X option, but no message when it dies. It just dies while executing a command (probably because the connection is dropped) A peek at netstat shows that the connections disappear from it before mclient dies. $ netstat -anp | grep 50000 tcp 0 0 127.0.0.1:50000 0.0.0.0:* LISTEN 29445/monetdbd udp 0 0 127.0.0.1:50000 0.0.0.0:* 29445/monetdbd unix 2 [ ACC ] STREAM LISTENING 3869978213 <(386)%20997-8213> 29445/monetdbd /tmp/.s.monetdb.50000 unix 2 [ ACC ] STREAM LISTENING 3869978215 <(386)%20997-8215> 29445/monetdbd /tmp/.s.merovingian.50000 unix 3 [ ] STREAM CONNECTED 3875263615 29486/mserver5 /tmp/.s.monetdb.50000 unix 2 [ ] STREAM CONNECTED 3871676942 29486/mserver5 /tmp/.s.monetdb.50000 $ netstat -anp | grep 50000 tcp 0 0 127.0.0.1:50000 0.0.0.0:* LISTEN 29445/monetdbd udp 0 0 127.0.0.1:50000 0.0.0.0:* 29445/monetdbd unix 2 [ ACC ] STREAM LISTENING 3869978213 <(386)%20997-8213> 29445/monetdbd /tmp/.s.monetdb.50000 unix 2 [ ACC ] STREAM LISTENING 3869978215 <(386)%20997-8215> 29445/monetdbd /tmp/.s.merovingian.50000 unix 2 [ ] STREAM CONNECTED 3871676942 29486/mserver5 /tmp/.s.monetdb.50000 After switching to the forward option (where this issue is less frequent to be bothersome) ===========================
From merovingian.log
2016-12-01 11:22:59 MSG merovingian[29824]: redirecting client (local) for database 'voc' to mapi:monetdb://cerberus:50001/voc Although for most part the connections are stable, if and when mclient dies, I do notice that the netstat entries are NOT being removed. (see the entries piling up at the bottom though there are no active client processes) $ netstat -anp | grep 50000 (Not all processes could be identified, non-owned process info will not be shown, you would have to be root to see it all.) tcp 0 0 127.0.0.1:50000 0.0.0.0:* LISTEN 29824/monetdbd tcp 1 0 127.0.0.1:50000 127.0.0.1:35870 CLOSE_WAIT 29824/monetdbd udp 0 0 127.0.0.1:50000 0.0.0.0:* 29824/monetdbd unix 2 [ ACC ] STREAM LISTENING 3876967185 29824/monetdbd /tmp/.s.monetdb.50000 unix 2 [ ACC ] STREAM LISTENING 3876967187 29824/monetdbd /tmp/.s.merovingian.50000 unix 2 [ ] STREAM CONNECTED 3877116313 29824/monetdbd /tmp/.s.monetdb.50000 unix 2 [ ] STREAM CONNECTED 3880819958 29824/monetdbd /tmp/.s.monetdb.50000 unix 2 [ ] STREAM CONNECTED 3878012589 29824/monetdbd /tmp/.s.monetdb.50000 unix 2 [ ] STREAM CONNECTED 3877885158 29824/monetdbd /tmp/.s.monetdb.50000 Thanks, Joseph