3 Commits

Author	SHA1	Message	Date
Reed Allman	3b261fc144	pipe swapparoo each slot (#721) ... * pipe swapparoo each slot previously, we made a pair of pipes for stdin and stdout for each container, and then handed them out to each call (slot) to use. this meant that multiple calls could have a handle on the same stdin pipe and stdout pipe to read/write to/from from fn's perspective and could mix input/output and get garbage. this also meant that each was blocked on the previous' reads. now we make a new pipe every time we get a slot, and swap it out with the previous ones. calls are no longer blocked from fn's perspective, and we don't have to worry about timing out dispatch for any hot format. there is still the issue that if a function does not finish reading the input from the previous task, from its perspective, and reads the next call's it can error out the second call. with fn deadline we provide the necessary tools to skirt this, but without some additional coordination am not sure this is a closable hole with our current protocols since terminating a previous calls input requires some protocol specific bytes to go in (json in particular is tricky). anyway, from fn's side fixing pipes was definitely a hole, but this client hole is still hanging out. there was an attempt to send an io.EOF but the issue is that will shut down docker's read on the stdin pipe (and the container). poop. this adds a test for this behavior, and makes sure 2 containers don't get launched. this also closes the response writer header race a little, but not entirely, I think there's still a chance that we read a full response from a function and get a timeout while we're changing the headers. I guess we need a thread safe header bucket, otherwise we have to rely on timings (racy). thinking on it. * fix stats mu race	2018-01-31 17:25:24 -08:00
Reed Allman	24aa911609	add FN_LOG_DEST for logs, fixup init (#663) ... * add FN_LOG_DEST for logs, fixup init * FN_LOG_DEST can point to a remote logging place (papertrail, whatever) * FN_LOG_PREFIX can add a prefix onto each log line sent to FN_LOG_DEST default remains stderr with no prefix. users need this to send to various logging backends, though it could be done operationally, this is somewhat simpler. we were doing some configuration stuff inside of init() for some of the global things. even though they're global, it's nice to keep them all in the normal server init path. we have had strange issues with the tracing setup, I tested the last repro of this repeatedly and didn't have any luck reproducing it, though maybe it comes back. * add docs	2018-01-09 14:27:50 -08:00
Reed Allman	71a88a991c	hang the runner, agent=new sheriff (#270) ... * fix docker build this is trivially incorrect since glide doesn't actually provide reproducible builds. the idea is to build with the deps that we have checked into git, so that we actually know what code is executing so that we might debug it... all for multi stage build instead of what we had, but adding the glide step is wrong. i added a loud warning so as to discourage this behavior in the future. * hang the runner, agent=new sheriff tl;dr agent is now runner, with a hopefully saner api the general idea is get rid of all the various 'task' structs now, change our terminology to only be 'calls' now, push a lot of the http construction of a call into the agent, allow calls to mutate their state around their execution easily and to simplify the number of code paths, channels and context timeouts in something [hopefully] easy to understand. this introduces the idea of 'slots' which are either hot or cold and are separate from reserving memory (memory is denominated in 'tokens' now). a 'slot' is essentially a container that is ready for execution of a call, be it hot or cold (it just means different things based on hotness). taking a look into Submit should make these relatively easy to grok. sorry, things were pretty broken especially wrt timings. I tried to keep good notes (maybe too good), to highlight stuff so that we don't make the same mistakes again (history repeating itself blah blah quote). even now, there is lots of work to do :) I encourage just reading the agent.go code, Submit is really simple and there's a description of how the whole thing works at the head of the file (after TODOs). call.go contains code for constructing calls, as well as Start / End (small atm). I did some amount of code massaging to try to make things simple / straightforward / fit reasonable mental model, but as always am open to critique (the more negative the better) as I'm just one guy and wth do i know... ----------------------------------------------------------------------------- below enumerates a number of changes as briefly as possible (heh..): models.Call all the things removes models.Task as models.Call is now what it previously was. models.FnCall is now rid of in favor of models.Call, despite the datastore only storing a few fields of it [for now]. we should probably store entire calls in the db, since app & route configurations can change at any given moment, it would be nice to see the parameters of each call (costs db space, obviously). this removes the endpoints for getting & deleting messages, we were just looping back to localhost to call the MQ (wtf? this was for iron integration i think) and just calls the MQ. changes the name of the FnLog to LogStore, confusing cause there's also a `FuncLogger` which uses the Logstore (punting). removes other `Fn` prefixed structs (redundant naming convention). removes some unused and/or weird structs (IDStatus, CompleteTime) updates the swagger makes the db methods consistent to use 'Call' nomenclature. remove runner nuisances: * push down registry stuff to docker driver * remove Environment / Stats stuff of yore * remove unused writers (now in FuncLogger) * remove 2 of the task types, old hot stuff, runner, etc fixes ram available calculation on startup to not always be 300GB (helps a lot on a laptop!) format for DOCKER_AUTH env now is not a list but a map (there are no docs, would prefer to get rid of this altogether anyway). the ~/.docker/cfg expected format is unchanged. removes arbitrary task queue, if a machine is out of ram we can probably just time out without queueing... (can open separate discussion) in any case the old one didn't really account well for hot tasks, it just lined everyone up in the task queue if there wasn't a place to run hot and then timed them out [even if a slot became free]. removes HEADER_ prefixing on any headers in the request to a invoke a call. (this was inconsistent with cli for test anyway) removes TASK_ID header sent in to hot only (this is a dupe of FN_CALL_ID, which has not been removed) now user functions can reply directly to the client. this means that for cold containers if they write to stdout it will send a 200 + headers. for hot containers, the user can reply directly to the client from the container, i.e. with its preferred status code / headers (vs. always getting a 200). the dispatch itself is a little http specific atm, i think we can add an interchange format but the current version is easily extended to add json for now, separate discussion. this eliminates a lot of the request/response rewriting and buffering we were doing (yey). now Dispatch ONLY does input and output, vs. managing the call timeout and having access to a call's fields. cache is pushed down into agent now instead of in the front end, would like to push it down to the datastore actually but it's here for now anyway. cache delete functions removed (b/c fn is distributed anyway?). added app caching, should help with latency. in general, a lot of server/runner.go got pushed down into the agent. i think it will be useful in testing to be able to construct calls without having to invoke http handlers + async also needs to construct calls without a handler. safe shutdown actually works now for everything (leaked / didn't wait on certain things before) now we're waiting for hot slots to open up while we're attempting to get ram to launch a container if we didn't find any hot slots to run the call in immediately. we can change this policy really easily now (no more channel jungle; still some channels). also looking for somewhere else to go while the container is launching now. slots now get sent _out_ of a container, vs. a container receiving calls, which makes this kind of policy easier to implement. this fixes a number of bugs around things like trying to execute calls against containers that have not and may never start and trying to launch a bazillion containers when there are no free containers. the driver api underwent some changes to make this possible (relatively minimal, added Wait). the easiest way to think about this is that allocating ram has moved 'up' instead of just wrapping launching containers, so that we can select on a channel trying to find ram. not dispatching hot calls to containers that died anymore either... the timeout is now started at the beginning of Submit, rather than Dispatch or the container itself having to manage the call timeout, which was an inaccurate way of doing things since finding a slot / allocating ram / pulling image can all take a non-trivial (timeout amount, even!) amount of time. this makes for much more reasonable response times from fn under load, there's still a little TODO about handling cold+timeout container removal response times but it's much improved. if call.Start is called with < call.timeout/2 time left, then the call will not be executed and return a timeout. we can discuss. this makes async play _a lot_ nicer, specifically. for large timeouts / 2 makes less sense. env is no longer getting upper cased (admittedly, this can look a little weird now). our whole route.Config/app.Config/env/headers stuff probably deserves a whole discussion... sync output no longer has the call id in json if there's an error / timeout. we could add this back to signify that it's _us_ writing these but this was out of place. FN_CALL_ID is still shipped out to get the id for sync calls, and async [server] output remains unchanged. async logs are now an entire raw http request (so that a user can write a 400 or something from their hot async container) async hot now 'just works' cold sync calls can now reply to the client before container removal, which shaves a lot of latency off of those (still eat start). still need to figure out async removal if timeout or something. ----------------------------------------------------------------------------- i've located a number of bugs that were generally inherited, and also added a number of TODOs in the head of the agent.go file according to robustness we probably need to add. this is at least at parity with the previous implementation, to my knowledge (hopefully/likely a good bit ahead). I can memorialize these to github quickly enough, not that anybody searches before adding bugs anyway (sigh). the big thing to work on next imo is async being a lot more robust, specifically to survive fn server failures / network issues. thanks for review (gulp)	2017-09-05 20:32:51 +03:00