--
You received this message because you are subscribed to the Google Groups "Ansible Project" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ansible-proje...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/0d59cf96-b053-4390-8dbb-663c70403104o%40googlegroups.com.
The only current process model is forking. There has been some work done to add a threaded process model, but there are some large hurdles to overcome.In practice, it is not necessarily more performant, and in many cases it was less performant, as it causes more CPU contention on a single core that is already resource constrained.
On Thu, Jun 4, 2020 at 1:18 PM Jagadeeshkumar Dittakavi <d.jagad...@gmail.com> wrote:
--I am a newbie to ansible but I got to explore how to run a tasks in parallel by spawing a thread for each task instead of a process. My requirement is to run the playbook on my localhost and there is no remote task execution needed.I also would like to wait for all threads to complete before I move on to a task that has to be serialised.Can I chose thread vs process when it comes to parallel task execution?If it is possible to spawn threads from ansible, are they equivalent to python greenthreads or pthreads or something else?Thank you in advance!
You received this message because you are subscribed to the Google Groups "Ansible Project" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ansible...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/0d59cf96-b053-4390-8dbb-663c70403104o%40googlegroups.com.
To unsubscribe from this group and stop receiving emails from it, send an email to ansible-proje...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/48f0ed5f-83c7-4bf4-a991-94ec78ce832eo%40googlegroups.com.
Yes, it would utilize the threading library in Python. The GIL is a primary cause to the CPU restrictions. Our main process that orchestrates all of the task executions is already heavily CPU bound, so adding additional threads to the same core can cause a decrease in performance. Assuming we create a process model plugin type, other process models are possible, such as using asyncio, concurrent.futures, gevent, etc. But I don't expect this work to be complete any time soon.So for now, consider forking the only process model for the near future.
On Thu, Jun 4, 2020 at 1:51 PM Jagadeeshkumar Dittakavi <d.jagad...@gmail.com> wrote:
Thank you for the prompt reply.. Just a curious question: Is the threading work that is underway based on python threads or pthreads or any other threading mechanism? As you mentioned that the threading model is not going to be performant, was the reason being the python's GIL?--
On Friday, June 5, 2020 at 12:01:14 AM UTC+5:30, Matt Martz wrote:The only current process model is forking. There has been some work done to add a threaded process model, but there are some large hurdles to overcome.In practice, it is not necessarily more performant, and in many cases it was less performant, as it causes more CPU contention on a single core that is already resource constrained.On Thu, Jun 4, 2020 at 1:18 PM Jagadeeshkumar Dittakavi <d.jagad...@gmail.com> wrote:--I am a newbie to ansible but I got to explore how to run a tasks in parallel by spawing a thread for each task instead of a process. My requirement is to run the playbook on my localhost and there is no remote task execution needed.I also would like to wait for all threads to complete before I move on to a task that has to be serialised.Can I chose thread vs process when it comes to parallel task execution?If it is possible to spawn threads from ansible, are they equivalent to python greenthreads or pthreads or something else?Thank you in advance!
You received this message because you are subscribed to the Google Groups "Ansible Project" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ansible...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/0d59cf96-b053-4390-8dbb-663c70403104o%40googlegroups.com.
--
You received this message because you are subscribed to the Google Groups "Ansible Project" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ansible...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/48f0ed5f-83c7-4bf4-a991-94ec78ce832eo%40googlegroups.com.
Command: ansible-playbook test_playbook.yml --forks=1
Processes:
root 69484 34309 9 04:50 pts/10 00:00:00 /usr/bin/python2 /usr/bin/ansible-playbook test_playbook.yml --forks=1
root 69509 1 0 04:50 ? 00:00:00 /usr/bin/python2 /root/.ansible/tmp/ansible-tmp-1591876209.82-38354017880191/async_wrapper.py 198806654079 50 /root/.ansible/tmp/ansible-tmp-1591876209.82-38354017880191/command.py _
root 69510 69509 0 04:50 ? 00:00:00 /usr/bin/python2 /root/.ansible/tmp/ansible-tmp-1591876209.82-38354017880191/async_wrapper.py 198806654079 50 /root/.ansible/tmp/ansible-tmp-1591876209.82-38354017880191/command.py _
root 69511 69510 0 04:50 ? 00:00:00 /usr/bin/python2 /root/.ansible/tmp/ansible-tmp-1591876209.82-38354017880191/command.py
root 69512 69511 1 04:50 ? 00:00:00 /usr/bin/python2 /tmp/ansible_f9ckPD/ansible_module_command.py
root 69520 69484 3 04:50 pts/10 00:00:00 /usr/bin/python2 /usr/bin/ansible-playbook test_playbook.yml --forks=1
Code:
[root@oracle-siha file_copy_test]# cat test_playbook.yml
- name: Testing processes
gather_facts: no
hosts: localhost
tasks:
- name: run sleep command
async: 50
poll: 0
command: sleep 20
register: res
- name: wait for the completion
async_status:
jid: "{{ res.ansible_job_id }}"
register: output
until: output.finished
delay: 5
retries: 10
To unsubscribe from this group and stop receiving emails from it, send an email to ansible-proje...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/f0093a03-d20b-4187-8bca-913e10770f5fo%40googlegroups.com.
There are a number of steps involved here.1. The primary playbook process spawns a worker2. The worker executes the async_wrapper for the command module3. The async_wrapper forks to daemonize4. The async_wrapper executes the transferred module5. The actual module is contained within what we call AnsiballZ which is a compressed archive, and it extracts and executes the actual python code6. Actual module executing.`forks` only limits how many workers can be launched by the primary playbook process, not how many processes will be spawned as a result of the worker.
To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/f0093a03-d20b-4187-8bca-913e10770f5fo%40googlegroups.com.
To unsubscribe from this group and stop receiving emails from it, send an email to ansible-proje...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/e87deb71-f620-461f-ac30-2c61931d8a51o%40googlegroups.com.