Summary: statistic for sequence number is needed by wormhole. setTickerCount is demanded for this statistic. I can't simply recordTick(max_sequence) when db recovers because the statistic iobject is owned by client and may/may not be reset during reopen. Eg. statistic is reset in mcrocksdb whereas it is not in db_stress. Therefore it is best to go with setTickerCount
Test Plan: ./db_stress ... --statistics=1 and observed expected sequence number
Reviewers: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D12327
Summary: Make Statistics usable by client
Test Plan: make check; db_bench
Reviewers: dhruba
Reviewed By: dhruba
Differential Revision: https://reviews.facebook.net/D10899
Summary: Statistics.h and histogram.h had double based api's to record values. Remove them as they are not used anywhere
Test Plan: make all check
Reviewers: haobo, dhruba
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D10815
Summary:
Use only the counter mechanism. Do away with
incNumFileOpens, incNumFileClose, incNumFileErrors
s/NULL/nullptr/g in db/table_cache.cc
Test Plan: make clean check
Reviewers: dhruba, heyongqiang, emayanke
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8841
Summary:
* Introduce is histogram in statistics.h
* stop watch to measure time.
* introduce two timers as a poc.
Replaced NULL with nullptr to fight some lint errors
Should be useful for google.
Test Plan:
ran db_bench and check stats.
make all check
Reviewers: dhruba, heyongqiang
Reviewed By: dhruba
CC: leveldb
Differential Revision: https://reviews.facebook.net/D8637
Summary:
make clean check OPT=-g fails
leveldb::DBStatistics::getTickerCount(leveldb::Tickers)’:
./db/db_statistics.h:34: error: ‘MAX_NO_TICKERS’ was not declared in this scope
util/ldb_cmd.cc:255: warning: left shift count >= width of type
Test Plan:
make clean check OPT=-g
Reviewers:
CC:
Task ID: #
Blame Rev:
Summary:
Prototype stat's collection. Diff is a good estimate of what
the final code will look like.
A few assumptions :
* Used a global static instance of the statistics object. Plan to pass
it to each internal function. Static allows metrics only at app
level.
* In the Ticker's do not do any locking. Depend on the mutex at each
function of LevelDB. If we ever remove the mutex, we should change
here too. The other option is use atomic objects anyways as there
won't be any contention as they will be always acquired only by one
thread.
* The counters are dumb, increment through lifecycle. Plan to use ods
etc to get last5min stat etc.
Test Plan:
made changes in db_bench
Ran ./db_bench --statistics=1 --num=10000 --cache_size=5000
This will print the cache hit/miss stats.
Reviewers: dhruba, heyongqiang
Differential Revision: https://reviews.facebook.net/D6441
Summary:
The db_bench test was not using the specified value for the max-file-open. Fixed.
The fs readhead is switched off.
Gather statistics about the table cache and print it out at the end of the tets run.
Test Plan: Revert Plan:
Reviewers: adsharma, sc
Reviewed By: adsharma
Differential Revision: https://reviews.facebook.net/D3441
Mayank Agarwal