calls, apps, and routes listing were previously returning the entire data set,
which just won't scale. this adds pagination with cursoring forward to each of
these endpoints (see the [docs](docs/definitions.md)).
the patch is really mostly tests, shouldn't be that bad to pick through.
some blarble about implementation is in order:
calls are sorted by ids but allow searching within certain `created_at` ranges
(finally). this is because sorting by `created_at` isn't feasible when
combined with paging, as `created_at` is not guaranteed to be unique -- id's
are (eliding theoreticals). i.e. on a page boundary, if there are 200 calls
with the same `created_at`, providing a `cursor` of that `created_at` will
skip over the remaining N calls with that `created_at`. also using id will be
better on the index anyway (well, less of them). yay having sortable ids! I
can't discern any issues doing this, as even if 200 calls have the same
created_at, they will have different ids, and the sort should allow paginating
them just fine. ids are also url safe, so the id works as the cursor value
just fine.
apps and routes are sorted by alphabetical order. as they aren't guaranteed to
be url safe, we are base64'ing them in the front end to a url safe format and
then returning them, and then base64 decoding them when we get them. this does
mean that they can be relatively large if the path/app is long, but if we
don't want to add ids then they were going to be pretty big anyway. a bonus
that this kind of obscures them. if somebody has better idea on formatting, by
all means.
notably, we are not using the sql paging facilities, and we are baking our own
based on cursors, which ends up being much more efficient for querying longer
lists of resources. this also should be easy to implement in other non-sql dbs
and the cursoring formats we can change on the fly since we are just exposing
them as opaque strings. the front end deals with the base64 / formatting, etc
and the back end is taking raw values (strfmt.DateTime or the id for calls).
the cursor that is being passed to/by the user is simply the last resource on the
previous page, so in theory we don't even need to return it, but it does make
it a little easier to use, also, cursor being blank on the last page depends
on page full-ness, so sometimes users will get a cursor when there are no
results on next page (1/N chance, and it's not really end of world -- actually
searching for the next thing would make things more complex). there are ample
tests for this behavior.
I've turned off all query parameters allowing `LIKE` queries on certain listing
endpoints, as we should not expose sql behavior through our API in the event
that we end up not using a sql db down the road. I think we should only allow
prefix matching, which sql can support as well as other types of databases
relatively cheaply, but this is not hooked up here as it didn't 'just work'
when I was fiddling with it (can add later, they're unnecessary and weren't
wired in before in front end).
* remove route listing across apps (unused)
* fix panic when doing `/app//`. this is prob possible for other types of
endpoints, out of scope here. added a guard in front of all endpoints for this
* adds `from_time` and `to_time` query parameters to calls, so you can e.g.
list the last hour of tasks. these are not required and default to
oldest/newest.
* hooked back up the datastore tests to the sql db, only run with sqlite atm,
but these are useful, added a lot to them too.
* added a bunch of tests to the front end, so pretty sure this all works now.
* added to swagger, we'll need to re-gen. also wrote some words about
pagination workings, I'm not sure how best to link to these, feedback welcome.
* not sure how we want to manage indexes, but we may need to add some (looking
at created_at, mostly)
* `?route` changed to `?path` in routes listing, to keep consistency with
everything else
* don't 404 when searching for calls where the route doesn't exist, just
return an empty list (it's a query param ffs)
closes#141
We still need to delete app and check how may rows affected in apps table.
But we don't really care about other tables and rows affected there: routes, calls, logs
We need to delete app out of loop to check for invalid numbers of rows affected:
- zero rows means nothing happend
Despite apps table, zero rows affected if valid case for routes, calls and logs
something still feels off with this, but i tinkered with it for a day-ish and
didn't come up with anything a whole lot better. doing a lot of the
maneuvering in the caller seemed better but it was just bloating up GetCall so
went back to having it basically like it was, but returning the limited
underlying buffer to read from so we can ship to the db.
some small changes to the LogStore interface, swapped it to take an
io.Reader instead of a string for more flexibility in the future while
essentially maintaining the same level of performance that we have now.
i'm guessing in the not so distant future we'll ship these to some s3 like
service and it would be better to stream them in than carry around a giant
string anyway. also, carrying around up to 1MB buffers in memory isn't great,
we may want to switch to file backed logs for calls, too. using io.Reader for
logs should make #279 more reasonable if/once we move to some s3-like thing,
we can stream from the log storage service direct to clients.
this fixes the span being out of whack and allows the 'right' context to be
used to upload logs (next to inserting the call). deletes the dbWriter we had,
and we just do this in call.End now (which makes sense to me at least).
removes the dupe code for making an stderr for hot / cold and simplifies the
way to get a func logger (no more 7 param methods yay).
closes#298
* 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)
we're routinely doing transactions which will hold up connections for some
time, it was pretty easy to run out of 30 conns from routine function
invocations. the 'right' thing is probably to add a config val to the url that
we can strip before passing into the db, but i'm not sure i want to have our
own query params in db urls, either.
we had this _almost_ right, in that we were trying, but we weren't masking the
error from the user response for any error we don't intend to show. this also
adds a stack trace from any internal server errors, so that we might be able
to track them down in the future (looking at you, 'context deadline
exceeded'). in addition, this adds a new `models.APIError` interface which all
of the errors in `models` now implement, and can be caught easily / added to
easily.
the front end now does no status rewriting based on api errors, now when we
get a non-nil error we can call `handleResponse(c, err)` with it and if it's a
proper error, return it to the user with the right status code, otherwise log
a stack trace and return `internal server error`. this cleans up a lot of the
front end code.
also rewrites start task ctx deadline exceeded as timeout. with iw we had
async tasks so we could start the clock later and it didn't matter, but now
with sync tasks time out sometimes just making docker calls, and we want the
task status to show up as timed out. we may want to just catch all this above
in addition to this, but this seems like the right thing to do.
remove squishing together errors. this was weird, now we return the first
error for the purposes of using the new err interface.
removed a lot of 5xx errors that really should have been 4xx errors. changed
some of the 400 errors to 409 errors, since they are from sending in
conflicting info and not a malformed request.
removed unused errors / useless errors (many were used for logging, and didn't
provide any context. now with stack traces we don't need context as much in
the logs).
replace default bolt option with sqlite3 option. the story here is that we
just need a working out of the box solution, and sqlite3 is just fine for that
(actually, likely better than bolt).
with sqlite3 supplanting bolt, we mostly have sql databases. so remove redis
and then we just have one package that has a `sql` implementation of the
`models.Datastore` and lean on sqlx to do query rewriting. this does mean
queries have to be formed a certain way and likely have to be ANSI-SQL (no
special features) but we weren't using them anyway and our base api is
basically done and we can easily extend this api as needed to only implement
certain methods in certain backends if we need to get cute.
* remove bolt & redis datastores (can still use as mqs)
* make sql queries work on all 3 (maybe?)
* remove bolt log store and use sqlite3
* shove the FnLog shit into the datastore shit for now (free pg/mysql logs...
just for demos, etc, not prod)
* fix up the docs to remove bolt references
* add sqlite3, sqlx dep
* fix up tests & mock stuff, make validator less insane
* remove put & get in datastore layer as nobody is using.
this passes tests which at least seem like they test all the different
backends. if we trust our tests then this seems to work great. (tests `make
docker-test-run-with-*` work now too)
