20:00:46 #startmeeting state-management 20:00:47 Meeting started Thu Jun 6 20:00:46 2013 UTC. The chair is harlowja. Information about MeetBot at http://wiki.debian.org/MeetBot. 20:00:48 Useful Commands: #action #agreed #help #info #idea #link #topic #startvote. 20:00:50 The meeting name has been set to 'state_management' 20:01:01 hi all! 20:01:05 hola 20:01:09 hey there 20:01:11 hi 20:01:13 hi hi 20:01:23 hello 20:01:29 howdy 20:01:46 so agenda for those that are interested (and/or missed the email since it was sent out late) 20:01:48 #link https://wiki.openstack.org/wiki/Meetings/StateManagement#Previous_meetings 20:01:53 hey guys 20:01:57 hi hi 20:02:11 oops wrong link 20:02:16 #link https://wiki.openstack.org/wiki/Meetings/StateManagement#Agenda_for_next_meeting 20:02:24 much betta 20:02:36 so lots of newness this week! 20:02:56 #topic where-everyone-is-at 20:03:19 just want to see how everyone is doing, any goodness that is being produced 20:03:22 I am reading your taskflow code 20:03:38 i'm still working on the cinder review (anvil took 1.5 days away from me this week so far) 20:03:56 i setup the launchpad site and a initial blueprints and bug (1) 20:04:36 jgriffith started looking over the review and seems like he's mostly happy (so far) 20:04:45 #link https://review.openstack.org/#/c/29862/ (patch set 8) 20:05:07 hemna have you been looking at anything for H2? 20:05:28 I've been slammed a bit 20:05:33 np 20:05:34 we can chat offline if you like 20:05:37 k 20:05:42 all good 20:06:07 i also talked more with devananda about some usage in ironic, hoepfully taskflow can help out there 20:06:10 do you have the launchpad url ? 20:06:29 https://launchpad.net/~taskflow-dev and https://launchpad.net/taskflow 20:07:03 jlucci, thanks 20:07:08 so i think kchenweijie has been continuing on the db work, correct? 20:07:15 thats right 20:07:20 and jlucci on the celery/distributed goods 20:07:31 https://review.openstack.org/#/c/32036/ 20:07:39 #link https://review.openstack.org/#/c/32036/ 20:07:43 ^^ distributed goods 20:07:45 jlucci: Error: "^" is not a valid command. 20:07:48 :) 20:08:05 all cool stuff, awesome work! 20:08:23 #topic launchpad 20:08:52 as jlucci pointed out, there is a new taskflow site and dev group! 20:08:57 #link https://launchpad.net/taskflow 20:08:57 nice 20:09:10 +1 jlucci 20:09:15 it seems to be a good place to register what people are working on and bugs and such 20:09:23 sound good to all? 20:09:34 yes 20:09:35 +1 20:09:43 feel free to join the https://launchpad.net/~taskflow-dev group also 20:09:47 i think its an open group 20:10:28 if not then let me know and i'll try to fix that setting :-p 20:10:36 pending approval :P 20:10:38 kk 20:11:07 hmmm, wonder why it can't be switched to open, well nm, either is fine i guess 20:11:20 #action harlowja investigate dev openness 20:12:34 so thats good stuff, nothing to exciting there :) 20:12:44 any questions about it, just bug me :-p 20:12:54 #topic stackforge 20:13:03 and we finally made it to stackforge! 20:13:06 #link https://github.com/stackforge/taskflow 20:13:09 yaaaa! 20:13:21 great! 20:13:23 the yahoo repo i removed so that we can not diverge there btw 20:13:34 so u might have to adjust your git remote if u were connected to the other one 20:13:37 just fyi 20:13:44 if that doesn't work out, i can try to help there 20:14:01 but that allows us to use review.openstack.org 20:14:29 right now there are 4 core people, more are welcome if they feel like they want to help out 20:14:42 jlucci devananda harlowja (and rohitk who isn't online) 20:15:15 i'd like to get hemna and other core members from involved teams in there, so they can have inputs (since the library will be used in there project) 20:15:23 hemna would u want to be in there? 20:15:51 sure 20:16:16 cool 20:16:29 hemna u have been added 20:16:35 rockin 20:16:58 i guess we can follow somewhat of the normal process for core people, or keep it pretty simple for now 20:17:07 the whole voting thing someday maybe, lol 20:17:27 sound good? 20:17:31 +1 20:17:40 +1 20:17:47 coolness 20:18:20 alright, any questions on that before next topic? 20:18:56 going once, going twice, sold 20:19:08 #topic fsm-pattern 20:19:34 sooo right now there exists a set of patterns in the taskflow library that allow users of the library to structure there tasks in different sequences 20:20:00 1 being a linear sequence (where a task can have inputs that are satisfied by a previous task, and output something for tasks 'down the line' to use) 20:20:45 the second being a graph sequence (using topological sort) which allows for tasks to have inputs satisfied by some other task in said graph, with the running order of the set of tasks determined by the dependency ordering 20:20:56 and right now thats currently the 2 patterns :) 20:21:04 ok 20:21:13 I think most of the cinder tasks will be linear no? 20:21:25 yes, i think those 2 patterns likely solve many of the problems 20:21:48 where u have action X -> Y -> Z 20:22:03 or X1->Y and X2->Y with Y->Z (graph) 20:22:19 *no loops allowed* 20:22:46 ok cool 20:23:00 sorry, but I have to run to the bus stop to get my kids...bbiab 20:23:46 np 20:24:17 but maybe its to early to tell, but there likely will be a desire for a more generic mechanism where u can structure your tasks via a FSM (inputs, outputs are part of tasks) and u could imagine a FSM table structure (X triggers Y after Z inputed provided) being defined that would allow for people creating FSMs with tasks 20:24:30 i think jlucci might be getting close to something like this 20:24:58 yupyup. Want me to give a quick overview of how that's working with the distributed pattern? 20:25:03 sure 20:25:36 Shweet. So, high-level overview, when you choose a distributed flow, a client in charge of task management is created for you 20:25:51 That client keeps track of all tasks and those task's "listeners/callbacks" 20:26:16 any example code? 20:26:16 So whenever a task completes successfully, the client is notified, and in turn notified all tasks that were listening for the now-successful task that it has completed 20:26:17 thats similar to the FSM 'state transition table' in a way right? 20:26:35 *to a FSM 'state transition table' 20:26:57 Rightright 20:27:05 Umm, as far as example code goes - 20:27:20 https://review.openstack.org/#/c/32036/ This contains the entirety of the distributed code right now 20:27:24 more specifically 20:27:35 the client 20:27:36 https://review.openstack.org/#/c/32036/1/taskflow/distributed/DTClient.py 20:27:45 and the pattern.py file ? 20:27:55 teh flow 20:27:56 https://review.openstack.org/#/c/32036/1/taskflow/patterns/distributed_flow.py 20:27:59 *distributed_flow.py 20:28:03 yeah, that's the pattern 20:28:03 ya, thx 20:28:21 pretty neat 20:28:31 And these (not-quite-functioning tests lolz) show how the flow would be used at the user-level 20:28:31 https://review.openstack.org/#/c/32036/1/taskflow/tests/unit/test_distributed_flow.py 20:28:53 I did follow up with the Galera guys, and they indicated that a Galera cluster (which could be deployed using heat) would be suitable for a backing store for a lock service because of the synchronous nature of the replication. 20:29:44 adrian_otto good to know 20:29:53 it would not be fast or scalable, but it would work for those that don't want to use ZK for whatever reason 20:30:42 adrian_otto cool, lets save that for a little bit after the distributed stuffs 20:31:22 jlucci so would there be a wrapper needed for the task class/decorator to make it work with that pattern, or would that be only internally used in the distributed_pattern class? 20:31:25 I'm just following up because I took a previous action item to ask that. 20:31:35 np :) 20:31:41 its much appreciated 20:32:21 jlucci the test looks pretty neat, seems to match how other tasks are formed (and connected into the FSM via the link method right?) 20:32:29 So, as of now, I'm using our task backend data structure, but not the actual task object 20:32:32 I'm using celery tasks 20:32:47 The choice for this is that celery has these cool things called 'signals' 20:32:55 that exposes the celery usage, i wonder if that can be something internal only to the distributed_flow pattern? 20:32:56 That act just like zookeeper notifiers 20:33:15 cool 20:33:23 Well, this might be reaching, but since you're declaring a task with a decorator right now 20:33:29 And that's what celery already does 20:34:01 We could just have the users always use @task.whatever to define a task, and then on our side, we'll know whether to use that to mean a celery or taskflow task 20:35:19 but then we are exposing users to celery, instead of nicely compartalmenalizing it in the distributed_flow 20:35:37 eck, bad spelling 20:36:11 oh, okay. Sorry. Misunderstood what you meant the first time 20:36:13 mmm 20:36:28 I think I could wrap it in the taskflow task object 20:36:40 Going to take some thinking through/hacking though. 20:36:43 or translate it when u do add() link() ? 20:36:51 are you suggesting that distributed and sigular tasks have the same interface, but the distributed has more attached? 20:37:03 ya 20:37:03 or are you suggesting divergent usage? 20:37:20 no, same task interface, how the distributed_flow connects them or wraps them is up to it 20:37:34 ok, good. 20:37:47 Could we add that as an action item for me? Or whatever the "go do this" thing is? 20:38:23 #action jlucci think about how taskflow decorator/task object can be translated in the distriubted_flow pattern to something that celery can use (thus not exposing celery to everyone) 20:38:26 i think that will do it 20:38:48 haha I think so. :P 20:38:51 #action bug josh if it makes no sense 20:39:17 in other words: "abstract celery". 20:39:32 \o 20:39:36 haha That's too simple adrian_otto We like to keep it overly difficult here. :P 20:39:48 until someday in the future when the only thing uses is the distributed_flow, then just say use celery at that point, lol 20:40:39 don't want to overly restrict what or how people can use taskflow this early in the game (if ever) 20:41:05 sorry i'm late... 20:41:08 np 20:41:12 devananda do all the work, thx 20:41:40 anything else jlucci for the distributed stuffs? we'll see if that might solve the FSM case by itself 20:42:01 if not we can see what else we can do 20:42:12 Nope. That's pretty much it. Just need to do some more hacking on it 20:42:22 coolness 20:42:31 #topic cinder/nova integration 20:42:41 so cinder is ongoing by me, slowly but surely i think 20:42:48 #link https://review.openstack.org/#/c/29862/ 20:42:59 i think hemna will get involved there when he gets some time and such 20:43:24 johnthetubaguy i think is doing some of the stuff in nova (but not using taskflow just yet, but doing something that should easily map to taskflow) 20:43:49 any ntt folks here?? i think they might be doing some nova stuff also 20:44:06 any heat folks? 20:44:25 I'm lurking. 20:44:34 But, I'm not Heat core. 20:44:49 kk, just don't want to lose heat focus also, i haven't been super involved in there meetings 20:45:07 make sure convection materializes using taskflow if thats being worked on 20:45:11 randallburt: welcome 20:45:20 hello everybody 20:45:25 There's enough overlap from the Rackspace side that we are keeping an eye towards Heat. 20:45:28 * kebray thinks 20:45:32 kebray thats much appreciated 20:45:33 how can I be of service? 20:45:57 jlucci sits amongst the rackspace Heat devs. 20:45:57 anything Heat can use from taskflow? 20:46:03 emerging recent needs? 20:46:19 nothing I can think of beyond its general stated purpose 20:46:51 adrian_otto kebray do we want to set any kind of mini-milestone where a piece of heat tries out taskflow? 20:46:53 I have not seen anything on the Heat ML on the taskflow subject 20:46:57 tbh, integration of it is low on the havana timeframe from what I can see, but progress on tf has looked pretty good so far, so you never know 20:47:10 a mini-milestone/piece of heat might be cool 20:47:36 heat is using a lot of python coroutines which are nifty but don't really lend themselves to this :( 20:47:37 the Heat core team feels we have a full plate for Havana, so they are unlikely to want a milestone... 20:47:46 its not likely but not impossible at this stage. there's scaling/multi engine work that would make it difficult at this point 20:48:02 what alexheneveld said ;) 20:48:28 interesting, how do coroutines usage make tasks harder to use? 20:48:33 but, that's not to say at some point we can't leverage jlucci and the Heat devs she sits next to and go after our own milestone. 20:48:38 at some point i see a major refactoring in heat to replace that nifty work with tasks but not much appetite for havana 20:49:07 alexheneveld agreed 20:49:10 alexheneveld ok, be interesting to get a braindump someday, is there anything written up that might be useful? 20:49:14 +1 20:49:27 the coroutines are about thread-sharing with a lot of back and forth 20:49:52 sounds like u guys made your own message passing? 20:50:08 jlucci may not know it yet, but I'm going to ask her help document a plan of integration for TF in Heat.. if we need to do any selling, discussion, I'd like to get that started early. 20:50:09 I really think that coroutine stuff will get yanked out in the future 20:50:13 nope, that part is more to do with higher concurrency 20:50:28 haha Awesome. I'll get right on that kebray. :p 20:50:34 kebray i guess jlucci knows now ;) 20:50:37 bumbumbuuuuuum 20:50:44 harlowja it's like that, but it is really a core python feature (just rarely used) - but short of it is you don't have access to task objects (on the plus side you don't have to write task objects, you can use core python syntax) 20:50:54 kebray: I'm happy to help out as needed 20:51:18 alexheneveld interesting 20:51:19 thanks adrian_otto! 20:51:37 IMO, its not a question of selling it as much as it is a question of timing. 20:51:41 back 20:51:42 and now's a bad time ;) 20:51:43 adrian_otto: +1 will have to go at some point - this work will be much better and i think they will agree, once it is clear 20:51:45 np 20:52:02 yep 20:52:09 alexheneveld: I agree 20:52:59 randallburt: Yes, there is plenty on the plate now, but it can't hurt to see about filling it in after H release 20:53:09 i wonder about how corountines are pretty much just individual FSM's (in a way), FSM's that connect to one another, but i guess u guys have thought about this more than me, haha 20:53:12 planting the seends for it 20:53:29 ok cool, not much time left! 20:53:34 they don't use them for communication 20:53:40 they use it as a concurrency intrument 20:53:46 sure, no harm in that. Would be nice to start the bp for it now and get the ball rolling before I summit anyway 20:53:55 s/intrument/instrument/ 20:54:16 yes, but I would wait before proposing that 20:54:21 as you said it's a matter of timing. 20:54:21 Yeah, and I'll talk to you offline randallburt, but I'd like to get an overview of the co-routine system if you find time soon 20:54:42 adrian_otto sure, if u have concurrent workflows that have ordering dependencies (start X after Y is produced by that other workflow Z) then it seems similar, but maybe not, haha 20:54:53 jlucci me too, so fill me in :) 20:54:55 jlucci: sure, I haven't kept up with Zane's fork, but we can look at it soon-ish 20:55:18 Yeah. That would be a good action item as well. Research heat co-routines or whatevers 20:55:35 and adrian_otto is right, its not a task issue as much as changes being made to the existing system that would make doing both a bit… messy 20:55:37 #action jlucci get overview of heat co-routine and report back? 20:55:45 harlowja: yes it is just fsm so would map to tasks but it is native python so not a small job (plus state is persisted). also i can't take any credit, it is all zaneb's work! 20:56:08 Works for me. :D 20:56:11 alexheneveld cool, looking forward to more info 20:56:29 #action alexheneveld get sam corbett from our side to give you chapter and verse :) 20:56:51 +- singing a choir song 20:57:02 lol 20:57:19 ok cool, so lets finish up with any action items from last time (probably should have started with this) 20:57:29 #topic action-items-that-should-of-been-done-at-the-start 20:57:41 adrian_otto so galleria stuff quick :) 20:57:55 provided update earlier. 20:57:55 speed IRC, lol 20:57:59 perfect :) 20:58:06 Galera should work. 20:58:19 of the options for a SQL backend, it's my preferred one. 20:58:24 * adrian_otto done 20:58:26 agreed 20:58:28 (two minute warning :) 20:59:04 adrian_otto would u want to update https://wiki.openstack.org/wiki/StructuredWorkflowLocks#Databases with anything u learned 20:59:11 1 minute, ahhhh 20:59:24 #adction adrian_otto to update wiki with Galera as a SQL option 20:59:37 #link https://wiki.openstack.org/wiki/StructuredWorkflowLocks#Databases 20:59:38 nopressurenopressure 20:59:42 ah 20:59:46 ok, anything else? 20:59:53 looks good guys 21:00:01 thx :) mailing list for anything else! 21:00:05 #action drian_otto to update wiki with Galera as a SQL option 21:00:12 Thanks guys! 21:00:14 #action adrian_otto to update wiki with Galera as a SQL option 21:00:21 bye folks 21:00:23 #endmeeting