mirror of https://github.com/BOINC/boinc.git
87 lines
2.5 KiB
PHP
87 lines
2.5 KiB
PHP
<?php
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require_once("docutil.php");
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page_head("Debugging server components");
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echo "
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<p>
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A grab-bag of techniques for debugging BOINC server software:
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<h2>Log files</h2>
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Most error conditions are reported in the log files.
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Make sure you know where these are.
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If you're interested in the history of a particular WU or result,
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grep for WU#12345 or RESULT#12345 (12345 represents the ID)
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in the log files.
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The html/ops pages also provide an interface for this.
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<h2>Database query tracing</h2>
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If you uncomment the symbol SHOW_QUERIES in db/db_base.C,
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and recompile everything,
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all database queries will be written to stderr
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(for daemons, this goes to log files;
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for command-line apps it's written to your terminal).
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This is verbose but extremely useful for tracking down
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database-level problems.
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<h2>Getting core dumps from the scheduler</h2>
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<p>
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In sched/main.C put:
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<pre>
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#define DUMP_CORE_ON_SEGV 1
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</pre>
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and recompile.
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<h2>Running the scheduler under a debugger</h2>
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The scheduler is a CGI program.
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It reads from stdin and writes to stdout,
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so you can also run it with a command-line debugger like gdb:
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<ul>
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<li>
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Copy the \"scheduler_request_X.xml\" file from a client to the
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machine running the scheduler. (X = your project URL)
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<li>
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Run the scheduler under the debugger, giving it this file as stdin,
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i.e.:
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".html_text("
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gdb cgi
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(set a breakpoint)
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r < scheduler_request_X.xml
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")."
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<li>
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You may have to doctor the database as follows:
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<pre>
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update host set rpc_seqno=0, rpc_time=0 where hostid=N
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</pre>
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to keep the scheduler from rejecting the request.
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</ul>
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This is useful for figuring out why your project is generating
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'no work available' messages.
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As an alternative to this, edit handle_request.C, and put
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a call to debug_sched(sreq, sreply, \"../debug_sched\") just
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before sreply.write(fout).
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Then, after recompiling, touch a file called 'debug_sched' in
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the project root directory.
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This will cause transcripts of all subsequent scheduler requests and
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replies to be written to the cgi-bin/ directory with separate
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small files for each request. The file names are sched_request_H_R
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where H=hostid and R=rpc sequence number.
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This can be turned off by deleting the 'debug_sched' file.
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<h2>MySQL interfaces</h2>
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You should become familiar with MySQL tools such as
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<ul>
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<li> mytop: like 'top' for MySQL
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<li> the mysql interpreter ('mysql') and in particular
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the 'show processlist;' query.
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<li> MySQLadmin: general-purpose web interface to MySQL
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</ul>
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";
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page_tail();
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