the metrics also show how this is split between select, insert,
update or delete activity. User activity is now shown showing the
number of different hosts that connect with the same username and
-the actiity of those users.
+the activity of those users. There are also statistics on mutex
+and sql stage timings.
### Installation
-Install and update this go package with `go get -u github.com/sjmudd/pstop`
+Install and update this go package with `go get -u github.com/sjmudd/pstop`.
+
+Note if you are looking for binaries for pstop then look here
+http://gobuild.io/github.com/sjmudd/pstop as a possible location.
+I have not tried this service but it looks ok.
+
+### Dependencies
+
+The following Non-core Go dependencies are:
+* github.com/sjmudd/mysql_defaults_file for connecting to MySQL via
+a defaults file.
+* github.com/nsf/termbox-go a library for creating cross-platform
+text-based interfaces.
### Configuration
-Access to MySQL is currently via a defaults-file which is assumed
-to be `~/.my.cnf`. This should probably be made more configurable.
-If you see a need for this please let me know.
+Access to MySQL can be made by one of the following methods:
+* Default: use a defaults-file named `~/.my.cnf`.
+* use an explicit defaults-file with `--defaults-file=/path/to/.my.cnf`.
+* connect to a host with `--host=somehost --port=999 --user=someuser --password=somepass`, or
+* connect via a socket with `--socket=/path/to/mysql.sock --user=someuser --password=somepass`
+
+The user if not specified will default to the contents of `$USER`.
+The port if not specified will default to 3306.
### Grants
`pstop` needs `SELECT` access to `performance_schema` tables. It
will not run if access to the required tables is not available.
+setup_instruments: To view the Mutex or Stage page pstop will try to
+change the configuration if needed and if you have grants to do this.
+If the server is --read-only or you don't have sufficient grants
+and the changes can not be made these pages may be empty.
+Pior to stopping pstop will restore the setup_instruments
+configuration back to its original settings if it had successfully
+updated the table when starting up.
+
### Screens
pstop has 5 different screens which get updated by default every second.
* Ops (operations) mode: order table activity by the number of operations MySQL performs on them.
* I/O mode: show where MySQL is spending it's time in file I/O.
* Locks mode: show order based on table locks
-* User mode: show ordering based on how long users are running queries, or the number of connections they have to MySQL.
+* User mode: show ordering based on how long users are running
+queries, or the number of connections they have to MySQL. This is
+really missing a feature in MySQL (see: http://bugs.mysql.com/75156)
+to provide higher resolution query times than seconds. It gives
+some info but if the queries are very short then the integer runtime
+in seconds makes the output far less interesting. Total idle time is also
+shown as this gives an indication of perhaps overly long idle queries,
+and the sum of the values here if there's a pile up may be interesting.
+* Mutex mode: show the ordering by mutex latency [1].
+* Stages mode: show the ordering by time in the different SQL query stages [1].
You can change the polling interval and switch between modes (see below).
+[1] pstop will try to configure the mutex and staging settings in
+setup_consumers if it can, and restore them when exiting if it
+changes something.
+
### Keys
The following keys allow you to navigate around the different pstop displays or to change it's behaviour.
* q - quit
* t - toggle between showing the statistics since resetting pstop started or you explicitly reset them (with 'z') [REL] or showing the statistics as collected from MySQL [ABS].
* z - reset statistics. That is counters you see are relative to when you "reset" statistics.
-* <tab> - change display modes between: latency, ops, file I/O, lock modes and user modes.
+* <tab> - change display modes between: latency, ops, file I/O, lock, user, mutex and stage modes.
* left arrow - change to previous screen
* right arrow - change to next screen
### Feedback
-Feedback and patches welcome.
+Feedback and patches welcome. I am especially interested in hearing
+from you if you are using pstop, or if you have ideas of how I can
+better use other information from the performance_schema tables to
+provide a more complete vision of what MySQL is doing or where it's
+busy.
Simon J Mudd
<sjmudd@pobox.com>
git://git.iain.cx/iain / pstop.git / blobdiff