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import htcondor
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print(htcondor.param["SCHEDD_LOG"]) # prints the schedd's current log file
print(htcondor.param.get("TOOL_LOG")) # print None, since TOOL_LOG isn't set by default
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htcondor.param["TOOL_LOG"] = "/tmp/log" # sets TOOL_LOG to /tmp/log
print(htcondor.param["TOOL_LOG"]) # prints /tmp/log, as set above
Note that assignments to param will persist only in memory; if we use reload_config to re-read the configuration files from disk, our change to TOOL_LOG disappears:
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print(htcondor.param.get("TOOL_LOG"))
htcondor.reload_config()
print(htcondor.param.get("TOOL_LOG"))
In HTCondor, a configuration prefix may indicate that a setting is specific to that daemon. By default, the Python binding's prefix is TOOL. If you would like to use the configuration of a different daemon, utilize the set_subsystem function:
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htcondor.param["TEST_FOO"] = "foo" # sets the default value of TEST_FOO to foo
htcondor.param["SCHEDD.TEST_FOO"] = "bar" # the schedd has a special setting for TEST_FOO
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print(htcondor.param['TEST_FOO']) # default access; should be 'foo'
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htcondor.set_subsystem('SCHEDD') # changes the running process to identify as a schedd.
print(htcondor.param['TEST_FOO']) # since we now identify as a schedd, should use the special setting of 'bar'
Between param, reload_config, and set_subsystem, we can explore the configuration of the local host.
What happens if we want to test the configuration of a remote daemon? For that, we can use the RemoteParam class.
The object is first initialized from the output of the Collector.locate method:
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master_ad = htcondor.Collector().locate(htcondor.DaemonTypes.Master)
print(master_ad['MyAddress'])
master_param = htcondor.RemoteParam(master_ad)
Once we have the master_param object, we can treat it like a local dictionary to access the remote daemon's configuration.
NOTE that the htcondor.param object attempts to infer type information for configuration values from the compile-time metadata while the RemoteParam object does not:
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print(repr(master_param['UPDATE_INTERVAL'])) # returns a string
print(repr(htcondor.param['UPDATE_INTERVAL'])) # returns an integer
In fact, we can even set the daemon's configuration using the RemoteParam object... if we have permission. By default, this is disabled for security reasons:
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master_param['UPDATE_INTERVAL'] = '500'
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htcondor.set_subsystem("TOOL")
htcondor.param['TOOL_DEBUG'] = 'D_FULLDEBUG'
htcondor.param['TOOL_LOG'] = '/tmp/log'
htcondor.enable_log() # Send logs to the log file (/tmp/foo)
htcondor.enable_debug() # Send logs to stderr; this is ignored by the web notebook.
print(open("/tmp/log").read()) # Print the log's contents.
An administrator can send administrative commands directly to the remote daemon. This is useful if you'd like a certain daemon restarted, drained, or reconfigured.
Because we have a personal HTCondor instance, we are the administrator - and we can test this out!
To send a command, use the top-level send_command function, provide a daemon location, and provide a specific command from the DaemonCommands enumeration. For example, we can reconfigure:
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print(master_ad['MyAddress'])
htcondor.send_command(master_ad, htcondor.DaemonCommands.Reconfig)
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import time
time.sleep(1)
log_lines = open(htcondor.param['MASTER_LOG']).readlines()
print(log_lines[-4:])
We can also instruct the master to shut down a specific daemon:
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htcondor.send_command(master_ad, htcondor.DaemonCommands.DaemonOff, "SCHEDD")
time.sleep(1)
log_lines = open(htcondor.param['MASTER_LOG']).readlines()
print(log_lines[-1])
Or even turn off the whole HTCondor instance:
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htcondor.send_command(master_ad, htcondor.DaemonCommands.OffFast)
time.sleep(1)
log_lines = open(htcondor.param['MASTER_LOG']).readlines()
print(log_lines[-1])
Let's turn HTCondor back on for future tutorials:
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import os
os.system("condor_master")
time.sleep(10) # give condor a few seconds to get started