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Diffstat (limited to 'bundled/tdb/docs/tracing.txt')
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diff --git a/bundled/tdb/docs/tracing.txt b/bundled/tdb/docs/tracing.txt deleted file mode 100644 index 98c5db9a..00000000 --- a/bundled/tdb/docs/tracing.txt +++ /dev/null @@ -1,46 +0,0 @@ -How And Why To Use TDB Tracing -============================== - -You can trace all TDB operations, using TDB_TRACE. It is not complete -(error conditions which expect to the logged will not always be traced -correctly, so you should set up a logging function too), but is designed -to collect benchmark-style traces to allow us to optimize TDB. - -Note: tracing is not efficient, and the trace files are huge: a -traverse of the database is particularly large! But they compress very -well with rzip (http://rzip.samba.org) - -How to gather trace files: --------------------------- -1) Uncomment /* #define TDB_TRACE 1 */ in tdb_private.h. -2) Rebuild TDB, and everything that uses it. -3) Run something. - -Your trace files will be called <tdbname>.trace.<pid>. These files -will not be overwritten: if the same process reopens the same TDB, an -error will be logged and tracing will be disabled. - -How to replay trace files: --------------------------- -1) For benchmarking, remember to rebuild tdb with #define TDB_TRACE commented - out again! -2) Grab the latest "replace_trace.c" from CCAN's tdb module (tools/ dir): - http://ccan.ozlabs.org/tarballs/tdb.tar.bz2 -3) Compile up replay_trace, munging as necessary. -4) Run replay_trace <scratch-tdb-name> <tracefiles>... - -If given more than one trace file (presumably from the same tdb) -replay_trace will try to figure out the dependencies between the operations -and fire off a child to run each trace. Occasionally it gets stuck, in -which case it will add another dependency and retry. Eventually it will -give a speed value. - -replay_trace can intuit the existence of previous data in the tdb (ie. -activity prior to the trace(s) supplied) and will prepopulate as -neccessary. - -You can run --quiet for straight benchmark results, and -n to run multiple -times (this saves time, since it need only calculate dependencies once). - -Good luck! -Rusty Russell <rusty@rustcorp.com.au> |