A network-accessible command-line interface to monitor a Zope 3 process.
Project description
Zope 3 Monitor Server
The Zope 3 monitor server is a server that runs in a Zope 3 process and that provides a command-line interface to request various bits of information. The server is zc.ngi based, so we can use the zc.ngi testing infrastructure to demonstrate it.
>>> import zc.ngi.testing >>> import zc.z3monitor>>> connection = zc.ngi.testing.TextConnection() >>> server = zc.z3monitor.Server(connection)
The server supports an extensible set of commands. It looks up commands as named zc.z3monitor.interfaces.IZ3MonitorPlugin plugins.
To see this, we’ll create a hello plugin:
>>> def hello(connection, name='world'):
... """Say hello
...
... Provide a name if you're not the world.
... """
... connection.write("Hi %s, nice to meet ya!\n" % name)
and register it:
>>> import zope.component, zc.z3monitor.interfaces >>> zope.component.provideUtility( ... hello, zc.z3monitor.interfaces.IZ3MonitorPlugin, 'hello')
Now we can give the hello command to the server:
>>> connection.test_input('hello\n')
Hi world, nice to meet ya!
-> CLOSE
We can pass a name:
>>> connection.test_input('hello Jim\n')
Hi Jim, nice to meet ya!
-> CLOSE
The server comes with a number of useful commands. Let’s register them so we can see what they do:
>>> zope.component.provideUtility(zc.z3monitor.help, ... zc.z3monitor.interfaces.IZ3MonitorPlugin, 'help') >>> zope.component.provideUtility(zc.z3monitor.interactive, ... zc.z3monitor.interfaces.IZ3MonitorPlugin, 'interactive') >>> zope.component.provideUtility(zc.z3monitor.quit, ... zc.z3monitor.interfaces.IZ3MonitorPlugin, 'quit') >>> zope.component.provideUtility(zc.z3monitor.monitor, ... zc.z3monitor.interfaces.IZ3MonitorPlugin, 'monitor') >>> zope.component.provideUtility(zc.z3monitor.dbinfo, ... zc.z3monitor.interfaces.IZ3MonitorPlugin, 'dbinfo') >>> zope.component.provideUtility(zc.z3monitor.zeocache, ... zc.z3monitor.interfaces.IZ3MonitorPlugin, 'zeocache') >>> zope.component.provideUtility(zc.z3monitor.zeostatus, ... zc.z3monitor.interfaces.IZ3MonitorPlugin, 'zeostatus')
The first is the help command. Giving help without input, gives a list of available commands:
>>> connection.test_input('help\n')
Supported commands:
dbinfo -- Get database statistics
hello -- Say hello
help -- Get help about server commands
interactive -- Turn on monitor's interactive mode
monitor -- Get general process info
quit -- Quit the monitor
zeocache -- Get ZEO client cache statistics
zeostatus -- Get ZEO client status information
-> CLOSE
We can get detailed help by specifying a command name:
>>> connection.test_input('help help\n') Help for help: <BLANKLINE> Get help about server commands <BLANKLINE> By default, a list of commands and summaries is printed. Provide a command name to get detailed documentation for a command. <BLANKLINE> -> CLOSE>>> connection.test_input('help hello\n') Help for hello: <BLANKLINE> Say hello <BLANKLINE> Provide a name if you're not the world. <BLANKLINE> -> CLOSE
The interactive command switches the monitor into interactive mode. As seen above, the monitor usually responds to a single command and then closes the connection. In “interactive mode”, the connection is not closed until the quit command is used. This can be useful when accessing the monitor via telnet for diagnostics.
>>> connection.test_input('interactive\n')
Interactive mode on. Use "quit" To exit.
>>> connection.test_input('help interactive\n')
Help for interactive:
<BLANKLINE>
Turn on monitor's interactive mode
<BLANKLINE>
Normally, the monitor releases the connection after a single command.
By entering the interactive mode, the monitor will not end the connection
until you enter the "quit" command.
<BLANKLINE>
>>> connection.test_input('help quit\n')
Help for quit:
<BLANKLINE>
Quit the monitor
<BLANKLINE>
This is only really useful in interactive mode (see the "interactive"
command).
<BLANKLINE>
>>> connection.test_input('quit\n')
Goodbye.
-> CLOSE
The other commands that come with the monitor use database information. They access databases as utilities. Let’s create some test databases and register them as utilities.
>>> from ZODB.tests.util import DB >>> main = DB() >>> from zope import component >>> import ZODB.interfaces >>> component.provideUtility(main, ZODB.interfaces.IDatabase) >>> other = DB() >>> component.provideUtility(other, ZODB.interfaces.IDatabase, 'other')
We also need to enable activity monitoring in the databases:
>>> import ZODB.ActivityMonitor >>> main.setActivityMonitor(ZODB.ActivityMonitor.ActivityMonitor()) >>> other.setActivityMonitor(ZODB.ActivityMonitor.ActivityMonitor())
Process Information
To get information about the process overall, use the monitor command:
>>> connection.test_input('help monitor\n') Help for monitor: <BLANKLINE> Get general process info <BLANKLINE> The minimal output has: <BLANKLINE> - The number of open database connections to the main database, which is the database registered without a name. - The virtual memory size, and - The resident memory size. <BLANKLINE> If there are old database connections, they will be listed. By default, connections are considered old if they are greater than 100 seconds old. You can pass a minimum old connection age in seconds. If you pass a value of 0, you'll see all connections. <BLANKLINE> If you pass a name after the integer, this is used as the database name. The database name defaults to the empty string (''). <BLANKLINE> -> CLOSE>>> connection.test_input('monitor\n') 0 VmSize: 35284 kB VmRSS: 28764 kB -> CLOSE>>> connection.test_input('monitor 100 other\n') 0 VmSize: 35284 kB VmRSS: 28764 kB -> CLOSE
Note that, as of this writing, the VmSize and VmRSS lines will only be present on a system with procfs. This generally includes many varieties of Linux, and excludes OS X and Windows.
Let’s create a couple of connections and then call z3monitor again with a value of 0:
>>> conn1 = main.open() >>> conn2 = main.open()>>> connection.test_input('monitor 0\n') 2 VmSize: 36560 kB VmRSS: 28704 kB 0.0 (0) 0.0 (0) -> CLOSE
The extra line of output gives connection debug info. If we set some additional input, we’ll see it:
>>> conn1.setDebugInfo('/foo') >>> conn2.setDebugInfo('/bar')>>> connection.test_input('monitor 0\n') 2 VmSize: 13048 kB VmRSS: 10084 kB 0.0 /bar (0) 0.0 /foo (0) -> CLOSE>>> conn1.close() >>> conn2.close()
Database Information
To get information about a database, use the dbinfo command:
>>> connection.test_input('help dbinfo\n') Help for dbinfo: <BLANKLINE> Get database statistics <BLANKLINE> By default statistics are returned for the main database. The statistics are returned as a single line consisting of the: <BLANKLINE> - number of database loads <BLANKLINE> - number of database stores <BLANKLINE> - number of connections in the last five minutes <BLANKLINE> - number of objects in the object caches (combined) <BLANKLINE> - number of non-ghost objects in the object caches (combined) <BLANKLINE> You can pass a database name, where "-" is an alias for the main database. <BLANKLINE> By default, the statistics are for a sampling interval of 5 minutes. You can request another sampling interval, up to an hour, by passing a sampling interval in seconds after the database name. <BLANKLINE> -> CLOSE>>> connection.test_input('dbinfo\n') 0 0 2 0 0 -> CLOSE
Let’s open a connection and do some work:
>>> conn = main.open() >>> conn.root()['a'] = 1 >>> import transaction >>> transaction.commit() >>> conn.root()['a'] = 1 >>> transaction.commit() >>> conn.close()>>> connection.test_input('dbinfo\n') 1 2 3 1 1 -> CLOSE
You can specify a database name. So, to get statistics for the other database, we’ll specify the name it was registered with:
>>> connection.test_input('dbinfo other\n')
0 0 0 0 0
-> CLOSE
You can use ‘-’ to name the main database:
>>> connection.test_input('dbinfo -\n')
1 2 3 1 1
-> CLOSE
You can specify a number of seconds to sample. For example, to get data for the last 10 seconds:
>>> connection.test_input('dbinfo - 10\n')
1 2 3 1 1
-> CLOSE
ZEO cache statistics
You can get ZEO cache statistics using the zeocache command.
>>> connection.test_input('help zeocache\n') Help for zeocache: <BLANKLINE> Get ZEO client cache statistics <BLANKLINE> The command returns data in a single line: <BLANKLINE> - the number of records added to the cache, <BLANKLINE> - the number of bytes added to the cache, <BLANKLINE> - the number of records evicted from the cache, <BLANKLINE> - the number of bytes evicted from the cache, <BLANKLINE> - the number of cache accesses. <BLANKLINE> By default, data for the main database are returned. To return information for another database, pass the database name. <BLANKLINE> -> CLOSE>>> connection.test_input('zeocache\n') 42 4200 23 2300 1000 -> CLOSE
You can specify a database name:
>>> connection.test_input('zeocache other\n')
42 4200 23 2300 1000
-> CLOSE
ZEO Cache status
The zeostatus command lets you get information about ZEO connection status:
>>> connection.test_input('help zeostatus\n') Help for zeostatus: <BLANKLINE> Get ZEO client status information <BLANKLINE> The command returns True if the client is connected and False otherwise. <BLANKLINE> By default, data for the main database are returned. To return information for another database, pass the database name. <BLANKLINE> -> CLOSE>>> connection.test_input('zeostatus\n') True -> CLOSE>>> connection.test_input('zeostatus other\n') True -> CLOSE
In this example, we’re using a faux ZEO connection. It has an attribute that determines whether it is connected or not. Id we change it, then the zeocache output will change:
>>> main._storage._is_connected = False
>>> connection.test_input('zeostatus\n')
False
-> CLOSE
Change History
0.6.0 (2008-09-14)
Features
The new interactive command makes connections continue through multiple commands until you use the quit command.
The monitor command takes an optional database argument (after the legacy long argument).
0.5.0 (2008-4-4)
Features
If the requested monitor port is in use, log and move on, rather than stopping the process with an exception. This lets zopectl debug work with a running instance.
0.4.1 (2008-3-31)
Initial release to PyPI
Bug Fixes
added zope.app.appsetup to dependencies, based on failing tests
Other
added comment that monitor examples currently fail on systems without procfs
tweaked setup.py for PyPI release
0.4.0 (2007-11-29)
New Features
Moved ZEO cache status to the zeostatus command.
0.3.0 (2007-11-29)
New Features
Commands are now provided as utilities. This means that z3monitor commands can be added by simply implementing simple utilities.
Added a working help command.
Added ZEO connection status to the zeocache output.
0.2.0 (2007-11-15)
New Features
Added a command to get ZEO cache statistics.
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