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<p><span style="font-size: 12pt;">Tatsuo,</span><br>
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the symptoms of the "hanged" pgpool are following:</div>
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1) DB applications fail with 2 types of errors:</div>
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- failed to prepare statement (PARSE)</div>
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- failed to extract ResultSet - failed selects</div>
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2) The problem is reproduced within a single JDBC connection, series of transactions are passed into it before the problem appears.</div>
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I'm deeply analysed pgpool logs from the series of failures and revealed a sample case (i.e. pgpool process). It's logs are attached.</div>
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I'm not sure I'm right but it seems the balancing logic is broken it its sequence of messages - how the are processed. I'am triggered by the fact it was sending PARSE messages to the both backends. </div>
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<span style="font-size: 12pt;"> </span><br>
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<span style="font-size: 12pt;">P/S: I was trying to attach the debugger to pgpool but I'm failed to detect a piece of code which I should focus at. Also it is a little bit hard to detect a pgpool process which should be debugged.</span></div>
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<div style="color: rgb(0, 0, 0);"><span style="font-size: 11pt;">Sergey.</span><br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Sergey Kim<br>
<b>Sent:</b> Wednesday, April 5, 2017 1:48 PM<br>
<b>To:</b> Tatsuo Ishii<br>
<b>Cc:</b> Boris Voskanov; pgpool-hackers@pgpool.net; Sergey Onuchin<br>
<b>Subject:</b> Re: [pgpool-hackers: 2227] Re: [pgpool-committers: 3836] pgpool: Branch refs/heads/bug271 was created</font>
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<p>... also it happens only when balancing is enabled in pgpool.</p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Sergey Kim<br>
<b>Sent:</b> Wednesday, April 5, 2017 1:34:45 PM<br>
<b>To:</b> Tatsuo Ishii<br>
<b>Cc:</b> Boris Voskanov; pgpool-hackers@pgpool.net; Sergey Onuchin<br>
<b>Subject:</b> Re: [pgpool-hackers: 2227] Re: [pgpool-committers: 3836] pgpool: Branch refs/heads/bug271 was created</font>
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<p>Tatsuo,</p>
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<p>the 2nd day of tests revealed a problem in pgpool which I trying to reproduce in a standalone test.</p>
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<p>Sometimes PARSE messages hang in pgpool and DB clients hang due to this reason. I'm just wanted to notify you on the problem. I'm fighting to reproduce it artificially.</p>
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<p>Sergey.</p>
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<div class="PlainText">...the primary message was cut</div>
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