[not for merge] start a monitoring radio plugin API #3315

benclifford · 2024-03-31T14:17:51Z

Description

This is the beginning of a monitoring radio plugin API, driven by some work with desc (where the choice of monitoring radio has been something to pay attention to performance-wise), by @ClaudiaCumberbatch who wants to plug in another radio, and the chronolog project where a hack sesssion resulted in sending some monitoring messages into chronolog. There are also possible uses in Globus Compute when wanting to observe task behaviour in future without having any supporting Parsl-style monitoring infrastructure.

Changed Behaviour

This API is a partial prototype and might not work quite right, but there is enough there to get feedback from potential users.

Prior to this PR monitoring configuration is sent as pair: a radio name (hard-coded in executor definitions since PR #2274, and not easily user selectable) along with information that can be used by some radios (for example, the monitoring router UDP listener endpoint).

After this PR, those fields are all replaced by a pickled configuration object, some instance of RadioConfig, which will be sent to the worker and used to create an appropriate radio. A user can now specify a RadioConfig instance (most likely a subclass of RadioConfig such as UDPRadioConfig) which contains whichever configuration values are relevant for that particular radio mode - for example, HTEXRadioConfig needs no further configuration, but UDPRadioConfig contains an IP address and UDP port.

This allows plugin-style out-of-codebase radios to be implemented without modifying the parsl source tree - that's a feature Parsl has been driving towards recently in many places to accomodate differing levels of code quality and support ability: most recently @ClaudiaCumberbatch's diaspora PR #3147, which this PR should accomodate without any diaspora-specific additions to the main Parsl codebase.

Type of change

New feature

…ugin Before this PR, the DataFlowKernel and each JobStatusPoller PolledExecutorFacade each opened a ZMQ connection to the monitoring router. These connections are not threadsafe, but (especially in the DFK case) no reasoning or checking stops the DFK's connection being used in multiple threads. Before this PR, the MonitoringHub presented a 'send' method and stored the DFK's ZMQ connection in self._dfk_channel, and each PolledExecutorFacade contained a copy of the ZMQ channel code to open its own channel, configured using parameters from the DFK passed in at construction. This PR: * moves the above uses to use the MonitoringRadio interface (which was originally designed for remote workers to send monitoring information, but seems ok here too) * has MonitoringHub construct an appropriate MonitoringRadio instance for use on the submit side, exposed as self.radio; * replaces the implementation of send with a new MultiprocessingQueueRadio which is thread safe but only works in the same multiprocessing environment as the launched monitoring database manager process (which is true on the submit side, but for example means this radio cannot be used on most remote workers) This work aligns with the prototype in #3315 (which pushes on monitoring radio configuration for remote workers) and pushes in the direction (without getting there) of allowing other submit-side hooks. This work removes some monitoring specific code from the JobStatusPoller, replacing it with a dependency injection style. This is part of work to move JobStatusPoller facade state into other classes, as part of job handling rearrangements in PR #3293 This PR will change how monitoring messages are delivered from the submitting process, and the most obvious thing I can think of that will change is how this will behave under load: heavily loaded messaging causing full buffers and other heavy-load symptoms will now behave as multiprocessing Queues do, rather than as ZMQ connections do. I have not attempted to characterise either of those modes.

…ugin (#3338) Before this PR, the DataFlowKernel and each JobStatusPoller PolledExecutorFacade each opened a ZMQ connection to the monitoring router. These connections are not threadsafe, but (especially in the DFK case) no reasoning or checking stops the DFK's connection being used in multiple threads. Before this PR, the MonitoringHub presented a 'send' method and stored the DFK's ZMQ connection in self._dfk_channel, and each PolledExecutorFacade contained a copy of the ZMQ channel code to open its own channel, configured using parameters from the DFK passed in at construction. This PR: * moves the above uses to use the MonitoringRadio interface (which was originally designed for remote workers to send monitoring information, but seems ok here too) * has MonitoringHub construct an appropriate MonitoringRadio instance for use on the submit side, exposed as self.radio; * replaces the implementation of send with a new MultiprocessingQueueRadio which is thread safe but only works in the same multiprocessing environment as the launched monitoring database manager process (which is true on the submit side, but for example means this radio cannot be used on most remote workers) This work aligns with the prototype in #3315 (which pushes on monitoring radio configuration for remote workers) and pushes in the direction (without getting there) of allowing other submit-side hooks. This work removes some monitoring specific code from the JobStatusPoller, replacing it with a dependency injection style. This is part of work to move JobStatusPoller facade state into other classes, as part of job handling rearrangements in PR #3293 This PR will change how monitoring messages are delivered from the submitting process, and the most obvious thing I can think of that will change is how this will behave under load: heavily loaded messaging causing full buffers and other heavy-load symptoms will now behave as multiprocessing Queues do, rather than as ZMQ connections do. I have not attempted to characterise either of those modes. Co-authored-by: Kevin Hunter Kesling <[email protected]>

This PR removes a use of multiprocessing fork-without-exec. At heart, this is how the interchange has wanted to be launched for some time (because of earlier remote interchange work). Launching multiprocessing fork caused a bunch of problems related to inheriteing state from from the parent submitting process that go away with this (jumbled logging topics, race conditions around at least logging-while-forking, inherited signal handlers). The configuration dictionary, previously passed in memory over a fork, is now sent in pickled form over stdin. Using pickle here rather than (eg.) JSON keeps the path open for sending richer configuration objects, beyond what can be encoded in JSON. This isn't something needed right now, but at least configurable monitoring radios (the immediate driving force behind this PR) are modelled around passing arbitrary configuration objects around to configure things - and so it seems likely that if interchange monitoring configuration is exposed to the user, richer objects would be passed here. See PR #3315 for monitoring radio prototype.

this is in preparation for pluggable/configurable radios: see PR #3315 in that future work, these receivers wont be launched unless configured... or at least, the UDP one won't (and similarly the filesystem one) and in pluggable mode we would expect arbitrary new receivers to exist so then theres no reason for these ones to be special this opens up, in a future PR, the ability to not need to poll at such a high frequency - or at all... the poll-timeout is to allow the other poll to happen, but this PR makes those two polls happen in two threads.

Ongoing monitoring radio work (see PR #3315) introduces per-radio configuration classes using *Radio names. This PR frees up the *Radio namespace for that use, by renaming non-user-exposed internal classes out of the way.

Prior to this PR, monitoring hub address and ZMQ port were stored as attributes of the DFK. The address also existed as an attribute on dfk.monitoring, and the ZMQ port was returned by dfk.monitoring.start Afte this PR, those values are not added to the DFK, but instead are accessed via dfk.monitoring. These two attributes are now only set on a new executor when monitoring is enabled, rather than always being intialised by the DFK. Default values now come from the executor __init__ method, which is a more usual style in Python for providing default values. See PR #3361 This is part of ongoing work to introduce more pluggable monitoring network connectivity - see PR #3315

Ongoing monitoring radio work (see PR #3315) introduces per-radio configuration classes using *Radio names. This PR frees up the *Radio namespace for that use, by renaming non-user-exposed internal classes out of the way.

this is in preparation for pluggable/configurable radios: see PR #3315 in that future work, these receivers wont be launched unless configured... or at least, the UDP one won't (and similarly the filesystem one) and in pluggable mode we would expect arbitrary new receivers to exist so then theres no reason for these ones to be special this opens up, in a future PR, the ability to not need to poll at such a high frequency - or at all... the poll-timeout is to allow the other poll to happen, but this PR makes those two polls happen in two threads.

Ongoing monitoring radio work (see PR #3315) introduces per-radio configuration classes using *Radio names. This PR frees up the *Radio namespace for that use, by renaming non-user-exposed internal classes out of the way.

Prior to this PR, monitoring hub address and ZMQ port were stored as attributes of the DFK. The address also existed as an attribute on dfk.monitoring, and the ZMQ port was returned by dfk.monitoring.start Afte this PR, those values are not added to the DFK, but instead are accessed via dfk.monitoring. These two attributes are now only set on a new executor when monitoring is enabled, rather than always being intialised by the DFK. Default values now come from the executor __init__ method, which is a more usual style in Python for providing default values. See PR #3361 This is part of ongoing work to introduce more pluggable monitoring network connectivity - see PR #3315

this is in preparation for pluggable/configurable radios: see PR #3315 in that future work, these receivers wont be launched unless configured... or at least, the UDP one won't (and similarly the filesystem one) and in pluggable mode we would expect arbitrary new receivers to exist so then theres no reason for these ones to be special this opens up, in a future PR, the ability to not need to poll at such a high frequency - or at all... the poll-timeout is to allow the other poll to happen, but this PR makes those two polls happen in two threads.

From an interchange perspective: this is a refactoring intended to clarify that the interchange isn't doing anything special wrt. monitoring messages and that it can send monitoring messages in the same way that remote workers can. From a monitoring perspective: this pulls ZMQ sender code out of the interchange and puts it in a place that is more natural for ongoing development. For example, a potential future use with Work Queue and Task Vine is that workers would also benefit from using ZMQ to send monitoring messages. In some potential use cases, it might be desirable to configure the radio used by the interchange instead of the hard-coded ZMQRadio. On-going work in draft PR #3315 addresses configuration of different types of radio and that work should be relevant here too.

this is in preparation for pluggable/configurable radios: see PR #3315 in that future work, these receivers wont be launched unless configured... or at least, the UDP one won't (and similarly the filesystem one) and in pluggable mode we would expect arbitrary new receivers to exist so then theres no reason for these ones to be special this opens up, in a future PR, the ability to not need to poll at such a high frequency - or at all... the poll-timeout is to allow the other poll to happen, but this PR makes those two polls happen in two threads.

A Parsl executor is configured with a submit-side monitoring radio sender, which is used by the BlockProviderExecutor to send block status messages to the monitoring subsystem. Parsl executors also have a notion of a remote monitoring radio, used by remote workers to sending monitoring messages. This can be confusing when both of these radio senders are referred to in the same piece of code, as happened in ongoing monitoring plugin development in draft PR #3315. This PR is intended to make this sitution much less ambiguous by avoiding the mention of a monitoring radio in executor code without qualifying whether it is a submit-side or remote-worker-side radio definition. A future PR from the #3315 stack will introduce other monitoring radio references with the remote prefix, replacing the current radio_mode and related attributes.

This is part of two ongoing strands of development: * Preparation for arbitrary monitoring radio receivers, where UDP is not special compared to other methods. This code separates out the UDP specific code making it easier to move around later (see development in PR #3315) * Avoiding poll-one-thing, poll-another-thing tight polling loops in favour of multiple blocking loops. The two router receiver sections used to run in a single tight non-blocking loop, each component waiting loop_freq (= 10 ms) for something to happen. After this PR, the separated loops are more amenable to longer blocking times - they only need to discover when exit event is set which probably can be more on the order of 1 second.

A Parsl executor is configured with a submit-side monitoring radio sender, which is used by the BlockProviderExecutor to send block status messages to the monitoring subsystem. Parsl executors also have a notion of a remote monitoring radio, used by remote workers to sending monitoring messages. This can be confusing when both of these radio senders are referred to in the same piece of code, as happened in ongoing monitoring plugin development in draft PR #3315. This PR is intended to make this sitution much less ambiguous by avoiding the mention of a monitoring radio in executor code without qualifying whether it is a submit-side or remote-worker-side radio definition. A future PR from the #3315 stack will introduce other monitoring radio references with the remote prefix, replacing the current radio_mode and related attributes.

From an interchange perspective: this is a refactoring intended to clarify that the interchange isn't doing anything special wrt. monitoring messages and that it can send monitoring messages in the same way that remote workers can. From a monitoring perspective: this pulls ZMQ sender code out of the interchange and puts it in a place that is more natural for ongoing development. For example, a potential future use with Work Queue and Task Vine is that workers would also benefit from using ZMQ to send monitoring messages. In some potential use cases, it might be desirable to configure the radio used by the interchange instead of the hard-coded ZMQRadio. On-going work in draft PR #3315 addresses configuration of different types of radio and that work should be relevant here too.

This is part of two ongoing strands of development: * Preparation for arbitrary monitoring radio receivers, where UDP is not special compared to other methods. This code separates out the UDP specific code making it easier to move around later (see development in PR #3315) * Avoiding poll-one-thing, poll-another-thing tight polling loops in favour of multiple blocking loops. The two router receiver sections used to run in a single tight non-blocking loop, each component waiting loop_freq (= 10 ms) for something to happen. After this PR, the separated loops are more amenable to longer blocking times - they only need to discover when exit event is set which probably can be more on the order of 1 second.

The main goals of this PR is to make _migrate_logs_to_internal much more clearly a message forwarder, rather than a message interpreter. This follows on from PR #2168 which introduces _dispatch_to_internal to dispatches messages based on their tag rather than on the queue the message was received on, and is part of an ongoing series to simplify the queue and routing structure inside the monitoring router and database code. Further PRs in preparation (in draft PR #3315) contain further simplifications building on this PR. After this PR: * the database manager will respond to a STOP message on any incoming queue, vs previously only on the priority queue. This is a consequence of treating the queues all the same now. * the database manager will not perform such strong validation of message structure based on message tag at this point. That's part of expecting the code to forward messages, not inspect them, with later inspecting code being the place to care abou structure. This only affects behaviour when invalid messages are sent. Related PRs and context: #3567 changes the monitoring router to be more of a router and to not inspect and modify certain in-transit messages. There is a long slow project to regularise queues: PR #2117 makes resource info messages look like other message so they can be dispatched alongside other message types. The priority queue was initially (as I understand it) introduced to attempt to address a race condition of message order arrival vs SQL database key constraints. The priority queue is an attempt to force certain messages to be processed before others (not in the priority queue). However a subsequent commit in 2019, 0a4b685, introduces a more robust approach because this priority queue approach does not work and so is not needed.

This PR is intended to consolidate monitoring message sending in the monitoring radio code. This is a step towards removing Python multiprocessing from the monitoring code base (see issue #2343) by making it clearer how to change to a different message send implementation (by swapping out the radio implementation and configuration) Compare to how the interchange forwards HTEXRadio messages onwards via some other radio (which right now is always the ZMQRadioSender) -- rather than having its own ZMQ code.

Prior to this PR, MonitoringHub had a logdir parameter which let the log directory be set separately from the DFK-level run directory. Other Parsl components generally don't let the user set this unless there is a specific reason. So this PR removes that feature, reducing the amount of state to be threaded around. When reading this patch, note that what the DFK calls the rundir is a different directory vs what a Config object calls the rundir.

in preparation for moving radio-specific radio code into these modules too

patch so far is overloading self.monitoring_radio for two different uses that should be clarified: submit side radio and worker side radio its a bit complicated for having a default radio (UDPRadio or HTEXRadio) even when monitoring is turned off: I should check that the radio receiver does not get activated in this case: for example: * test that broken radio activation causes a startup error * test that configuration with broken radio doesn't cause a startup error when monitoringhub is not configured zmq radio should always listen, and be the place where all radio receivers send their data. udp radio and filesystem radio should turn into separate... something... processes? for prototyping i guess it doesn't matter where I make them live, but the most behaviour preserving would keep them somehow separated?

In subsequent PRs, these modules will get more radio-specific code, as part of PR #3315 monitoring radio plugin work: for example, the receiving code for each radio should move here too. I used `git show --color-moved` to check that the moved RadioSender definitions were not changed.

In subsequent PRs, these modules will get more radio-specific code, as part of PR #3315 monitoring radio plugin work: for example, the receiving code for each radio should move here too. I used `git show --color-moved` to check that the moved RadioSender definitions were not changed. # Changed Behaviour none ## Type of change - Code maintenance/cleanup

benclifford mentioned this pull request Mar 31, 2024

add diaspora radio and is able to send resource info #3147

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benclifford mentioned this pull request Apr 10, 2024

split monitoring router into a UDP part and a ZMQ part #3332

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benclifford mentioned this pull request Apr 10, 2024

Replace DFK and JobStatusPoller monitoring zmq channels with Queue radio #3338

Merged

benclifford mentioned this pull request Apr 17, 2024

Demo of hacking in custom registration behaviour into interchange registrations #3359

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benclifford mentioned this pull request May 16, 2024

Factor radio selection in monitoring worker-side code #3432

Merged

benclifford mentioned this pull request Jun 12, 2024

Launch interchange as a fresh process #3463

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benclifford force-pushed the benc-monitoring-pluggable-radios branch from 9ad2288 to 7d7723b Compare June 24, 2024 18:12

benclifford force-pushed the benc-monitoring-pluggable-radios branch 2 times, most recently from b53cabd to d5d8409 Compare June 24, 2024 20:10

benclifford force-pushed the benc-monitoring-pluggable-radios branch 2 times, most recently from 9e8c6e0 to 2f9589d Compare July 11, 2024 09:28

benclifford mentioned this pull request Jul 11, 2024

Free up the *Radio namespace for future config structures #3520

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benclifford mentioned this pull request Jul 11, 2024

Don't copy monitoring address/port parameters into the DFK. #3522

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benclifford force-pushed the benc-monitoring-pluggable-radios branch from 2f9589d to 466c2db Compare July 18, 2024 09:15

benclifford force-pushed the benc-monitoring-pluggable-radios branch 2 times, most recently from 72c98fa to c179253 Compare July 26, 2024 20:44

benclifford mentioned this pull request Jul 31, 2024

Factor interchange monitoring code into a ZMQRadioSender #3556

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benclifford force-pushed the benc-monitoring-pluggable-radios branch from d2ee35c to ddb214a Compare July 31, 2024 11:38

benclifford mentioned this pull request Jul 31, 2024

Rename submit-side monitoring radio for clarification #3557

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benclifford mentioned this pull request Jul 31, 2024

Split monitoring router into two radio-specific receiver threads #3558

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benclifford force-pushed the benc-monitoring-pluggable-radios branch 2 times, most recently from 7132279 to 4f314da Compare August 15, 2024 14:02

benclifford mentioned this pull request Aug 16, 2024

Remove monitoring queue tag switch monitoring db pre-router #3587

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benclifford force-pushed the benc-monitoring-pluggable-radios branch 2 times, most recently from 2f1c15a to b6de72d Compare August 26, 2024 11:31

benclifford force-pushed the benc-monitoring-pluggable-radios branch 3 times, most recently from d2edccc to d175376 Compare October 31, 2024 15:39

benclifford force-pushed the benc-monitoring-pluggable-radios branch from d175376 to 60f8eb2 Compare November 7, 2024 11:09

benclifford added 4 commits November 14, 2024 14:07

put each radio type in its own module

1d55ca3

in preparation for moving radio-specific radio code into these modules too

benclifford force-pushed the benc-monitoring-pluggable-radios branch from 60f8eb2 to c66230b Compare November 14, 2024 16:39

benclifford mentioned this pull request Nov 29, 2024

Move monitoring radios to own modules #3707

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[not for merge] start a monitoring radio plugin API #3315

[not for merge] start a monitoring radio plugin API #3315

benclifford commented Mar 31, 2024

[not for merge] start a monitoring radio plugin API #3315

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[not for merge] start a monitoring radio plugin API #3315

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benclifford commented Mar 31, 2024

Description

Changed Behaviour

Type of change