* Initial stab at the protocol
* initial protocol sketch for node pool manager
* Added http header frame as a message
* Force the use of WithAgent variants when creating a server
* adds grpc models for node pool manager plus go deps
* Naming things is really hard
* Merge (and optionally purge) details received by the NPM
* WIP: starting to add the runner-side functionality of the new data plane
* WIP: Basic startup of grpc server for pure runner. Needs proper certs.
* Go fmt
* Initial agent for LB nodes.
* Agent implementation for LB nodes.
* Pass keys and certs to LB node agent.
* Remove accidentally left reference to env var.
* Add env variables for certificate files
* stub out the capacity and group membership server channels
* implement server-side runner manager service
* removes unused variable
* fixes build error
* splits up GetCall and GetLBGroupId
* Change LB node agent to use TLS connection.
* Encode call model as JSON to send to runner node.
* Use hybrid client in LB node agent.
This should provide access to get app and route information for the call
from an API node.
* More error handling on the pure runner side
* Tentative fix for GetCall problem: set deadlines correctly when reserving slot
* Connect loop for LB agent to runner nodes.
* Extract runner connection function in LB agent.
* drops committed capacity counts
* Bugfix - end state tracker only in submit
* Do logs properly
* adds first pass of tracking capacity metrics in agent
* maked memory capacity metric uint64
* maked memory capacity metric uint64
* removes use of old capacity field
* adds remove capacity call
* merges overwritten reconnect logic
* First pass of a NPM
Provide a service that talks to a (simulated) CP.
- Receive incoming capacity assertions from LBs for LBGs
- expire LB requests after a short period
- ask the CP to add runners to a LBG
- note runner set changes and readvertise
- scale down by marking runners as "draining"
- shut off draining runners after some cool-down period
* add capacity update on schedule
* Send periodic capcacity metrics
Sending capcacity metrics to node pool manager
* splits grpc and api interfaces for capacity manager
* failure to advertise capacity shouldn't panic
* Add some instructions for starting DP/CP parts.
* Create the poolmanager server with TLS
* Use logrus
* Get npm compiling with cert fixups.
* Fix: pure runner should not start async processing
* brings runner, nulb and npm together
* Add field to acknowledgment to record slot allocation latency; fix a bug too
* iterating on pool manager locking issue
* raises timeout of placement retry loop
* Fix up NPM
Improve logging
Ensure that channels etc. are actually initialised in the structure
creation!
* Update the docs - runners GRPC port is 9120
* Bugfix: return runner pool accurately.
* Double locking
* Note purges as LBs stop talking to us
* Get the purging of old LBs working.
* Tweak: on restart, load runner set before making scaling decisions.
* more agent synchronization improvements
* Deal with teh CP pulling out active hosts from under us.
* lock at lbgroup level
* Send request and receive response from runner.
* Add capacity check right before slot reservation
* Pass the full Call into the receive loop.
* Wait for the data from the runner before finishing
* force runner list refresh every time
* Don't init db and mq for pure runners
* adds shutdown of npm
* fixes broken log line
* Extract an interface for the Predictor used by the NPM
* purge drained connections from npm
* Refactor of the LB agent into the agent package
* removes capacitytest wip
* Fix undefined err issue
* updating README for poolmanager set up
* ues retrying dial for lb to npm connections
* Rename lb_calls to lb_agent now that all functionality is there
* Use the right deadline and errors in LBAgent
* Make stream error flag per-call rather than global otherwise the whole runner is damaged by one call dropping
* abstracting gRPCNodePool
* Make stream error flag per-call rather than global otherwise the whole runner is damaged by one call dropping
* Add some init checks for LB and pure runner nodes
* adding some useful debug
* Fix default db and mq for lb node
* removes unreachable code, fixes typo
* Use datastore as logstore in API nodes.
This fixes a bug caused by trying to insert logs into a nil logstore. It
was nil because it wasn't being set for API nodes.
* creates placement abstraction and moves capacity APIs to NodePool
* removed TODO, added logging
* Dial reconnections for LB <-> runners
LB grpc connections to runners are established using a backoff stategy
in event of reconnections, this allows to let the LB up even in case one
of the runners go away and reconnect to it as soon as it is back.
* Add a status call to the Runner protocol
Stub at the moment. To be used for things like draindown, health checks.
* Remove comment.
* makes assign/release capacity lockless
* Fix hanging issue in lb agent when connections drop
* Add the CH hash from fnlb
Select this with FN_PLACER=ch when launching the LB.
* small improvement for locking on reloadLBGmembership
* Stabilise the list of Runenrs returned by NodePool
The NodePoolManager makes some attempt to keep the list of runner nodes advertised as
stable as possible. Let's preserve this effort in the client side. The main point of this
is to attempt to keep the same runner at the same inxed in the []Runner returned by
NodePool.Runners(lbgid); the ch algorithm likes it when this is the case.
* Factor out a generator function for the Runners so that mocks can be injected
* temporarily allow lbgroup to be specified in HTTP header, while we sort out changes to the model
* fixes bug with nil runners
* Initial work for mocking things in tests
* fix for anonymouse go routine error
* fixing lb_test to compile
* Refactor: internal objects for gRPCNodePool are now injectable, with defaults for the real world case
* Make GRPC port configurable, fix weird handling of web port too
* unit test reload Members
* check on runner creation failure
* adding nullRunner in case of failure during runner creation
* Refactored capacity advertisements/aggregations. Made grpc advertisement post asynchronous and non-blocking.
* make capacityEntry private
* Change the runner gRPC bind address.
This uses the existing `whoAmI` function, so that the gRPC server works
when the runner is running on a different host.
* Add support for multiple fixed runners to pool mgr
* Added harness for dataplane system tests, minor refactors
* Add Dockerfiles for components, along with docs.
* Doc fix: second runner needs a different name.
* Let us have three runners in system tests, why not
* The first system test running a function in API/LB/PureRunner mode
* Add unit test for Advertiser logic
* Fix issue with Pure Runner not sending the last data frame
* use config in models.Call as a temporary mechanism to override lb group ID
* make gofmt happy
* Updates documentation for how to configure lb groups for an app/route
* small refactor unit test
* Factor NodePool into its own package
* Lots of fixes to Pure Runner - concurrency woes with errors and cancellations
* New dataplane with static runnerpool (#813)
Added static node pool as default implementation
* moved nullRunner to grpc package
* remove duplication in README
* fix go vet issues
* Fix server initialisation in api tests
* Tiny logging changes in pool manager.
Using `WithError` instead of `Errorf` when appropriate.
* Change some log levels in the pure runner
* fixing readme
* moves multitenant compute documentation
* adds introduction to multitenant readme
* Proper triggering of system tests in makefile
* Fix insructions about starting up the components
* Change db file for system tests to avoid contention in parallel tests
* fixes revisions from merge
* Fix merge issue with handling of reserved slot
* renaming nulb to lb in the doc and images folder
* better TryExec sleep logic clean shutdown
In this change we implement a better way to deal with the sleep inside
the for loop during the attempt for placing a call.
Plus we added a clean way to shutdown the connections with external
component when we shut down the server.
* System_test mysql port
set mysql port for system test to a different value to the one set for
the api tests to avoid conflicts as they can run in parallel.
* change the container name for system-test
* removes flaky test TestRouteRunnerExecution pending resolution by issue #796
* amend remove_containers to remove new added containers
* Rework capacity reservation logic at a higher level for now
* LB agent implements Submit rather than delegating.
* Fix go vet linting errors
* Changed a couple of error levels
* Fix formatting
* removes commmented out test
* adds snappy to vendor directory
* updates Gopkg and vendor directories, removing snappy and addhing siphash
* wait for db containers to come up before starting the tests
* make system tests start API node on 8085 to avoid port conflict with api_tests
* avoid port conflicts with api_test.sh which are run in parallel
* fixes postgres port conflict and issue with removal of old containers
* Remove spurious println
* update vendor directory, add go.opencensus.io
* update imports
* oops
* s/opentracing/opencensus/ & remove prometheus / zipkin stuff & remove old stats
* the dep train rides again
* fix gin build
* deps from last guy
* start in on the agent metrics
* she builds
* remove tags for now, cardinality error is fussing. subscribe instead of register
* update to patched version of opencensus to proceed for now TODO switch to a release
* meh
fix imports
* println debug the bad boys
* lace it with the tags
* update deps again
* fix all inconsistent cardinality errors
* add our own logger
* fix init
* fix oom measure
* remove bugged removal code
* fix s3 measures
* fix prom handler nil
* push down app listeners to a datastore
fnext.NewDatastore returns a datastore that wraps the appropriate methods for
AppListener in a Datastore implementation. this is more future proof than
needing to wrap every call of GetApp/UpdateApp/etc with the listeners, there
are a few places where this can happen and it seems like the AppListener
behavior is supposed to wrap the datastore, not just the front end methods
surrounding CRUD ops on an app. the hairy case that came up was when fiddling
with the create/update route business.
this changes the FireBeforeApp* ops to be an AppListener implementation itself
rather than having the Server itself expose certain methods to fire off the
app listeners, now they're on the datastore itself, which the server can
return the instance of.
small change to BeforeAppDelete/AfterAppDelete -- we were passing in a half
baked struct with only the name filled in and not filling in the fields
anywhere. this is mostly just misleading, we could fill in the app, but we
weren't and don't really want to, it's more to notify of an app deletion event
so that an extension can behave accordingly instead of letting a user inspect
the app. i know of 3 extensions and the changes required to update are very
small.
cleans up all the front end implementations FireBefore/FireAfter.
this seems potentially less flexible than previous version if we do want to
allow users some way to call the database methods without using the
extensions, but that's exactly the trade off, as far as the AppListener's are
described it seems heavily implied that this should be the case.
mostly a feeler, for the above reasons, but this was kind of odorous so just
went for it. we do need to lock in the extension api stuff.
* hand em an app that's been smokin the reefer
i would split this commit in two if i were a good dev.
the pprof stuff is really useful and this only samples when called. this is
pretty standard go service stuff. expvar is cool, too.
the additional spannos have turned up some interesting tid bits... gonna slide
em in
1) in dind, prevent SIGINT reaching to dockerd. This kills
docker and prevents shutdown as fn server is trying to stop.
2) as init process, always reap child processes.
* 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
* Ship call logs to the user as text/plain instead of JSON
* Fixing swagger doc
* c.String instead of c.JSON
* Make Logs API backward compatible
* Loop over accepted MIME types
* Bump swagger API version
* Fix client build script
previous version was producing the following "couldn't find a swagger spec"
* Logs API regression test
* Write response body without buffering
* Switch JSON and text/plain cases
* Handle Accepted content types properly
* More solid response content type handling
* Write HTTP 406 with corresponding error body
* Remove unused import
* Use handleErrorResponse
* Use retry func while trying to ping SQL datastore
- implements retry func specifically for SQL datastore ping
- fmt fixes
- using sqlx.Db.PingContext instead of sqlx.Db.Ping
- propogate context to SQL datastore
* Rely on context from ServerOpt
* Consolidate log instances
* Cleanup
* Fix server usage in API tests
* allow user configured agent in full node
this should keep the old default behavior but allow users to pass in a
configured agent to configure the server themselves, without having to worry
about a russian agent being a british agent.
also closes any agent given to an api node.
closes#623
* don't close agent in runner test
this patch has no behavior changes, changes are:
* server.Datastore() -> server.datastore
* server.MQ -> server.mq
* server.LogDB -> server.logstore
* server.Agent -> server.agent
these were at a minimum not uniform. further, it's probably better to force
configuration through initialization in `server.New` to ensure thread safety
of referencing if someone does want to modify these as well as forcing things
into our initialization path and reducing the surface area of the Server
abstraction.
* fix configuration of agent and server to be future proof and plumb in the hybrid client agent
* fixes up the tests, turns off /r/ on api nodes
* fix up defaults for runner nodes
* shove the runner async push code down into agent land to use client
* plumb up async-age
* return full call from async dequeue endpoint, since we're storing a whole
call in the MQ we don't need to worry about caching of app/route [for now]
* fast safe shutdown of dequeue looper in runner / tidying of agent
* nice errors for path not found against /r/, /v1/ or other path not found
* removed some stale TODO in agent
* mq backends are only loud mouths in debug mode now
* update tests
* Add caching to hybrid client
* Fix HTTP error handling in hybrid client.
The type switch was on the value rather than a pointer.
* Gofmt.
* Better caching with a nice caching wrapper
* Remove datastore cache which is now unused
* Don't need to manually wrap interface methods
* Go fmt
* so it begins
* add clarification to /dequeue, change response to list to future proof
* Specify that runner endpoints are also under /v1
* Add a flag to choose operation mode (node type).
This is specified using the `FN_NODE_TYPE` environment variable. The
default is the existing behaviour, where the server supports all
operations (full API plus asynchronous and synchronous runners).
The additional modes are:
* API - the full API is available, but no functions are executed by the
node. Async calls are placed into a message queue, and synchronous
calls are not supported (invoking them results in an API error).
* Runner - only the invocation/route API is present. Asynchronous and
synchronous invocation requests are supported, but asynchronous
requests are placed onto the message queue, so might be handled by
another runner.
* Add agent type and checks on Submit
* Sketch of a factored out data access abstraction for api/runner agents
* Fix tests, adding node/agent types to constructors
* Add tests for full, API, and runner server modes.
* Added atomic UpdateCall to datastore
* adds in server side endpoints
* Made ServerNodeType public because tests use it
* Made ServerNodeType public because tests use it
* fix test build
* add hybrid runner client
pretty simple go api client that covers surface area needed for hybrid,
returning structs from models that the agent can use directly. not exactly
sure where to put this, so put it in `/clients/hybrid` but maybe we should
make `/api/runner/client` or something and shove it in there. want to get
integration tests set up and use the real endpoints next and then wrap this up
in the DataAccessLayer stuff.
* gracefully handles errors from fn
* handles backoff & retry on 500s
* will add to existing spans for debuggo action
* minor fixes
* meh
* Extend extension mechanism to support per-route API extensions
* Tidy up comment
* Remove print statement
* Minor improvement to README
* Avoid calling c.Request.Context() twice
* add minio-go dep, update deps
* add minio s3 client
minio has an s3 compatible api and is an open source project and, notably, is
not amazon, so it seems best to use their client (fwiw the aws-sdk-go is a
giant hair ball of things we don't need, too). it was pretty easy and seems
to work, so rolling with it. also, minio is a totally feasible option for fn
installs in prod / for demos / for local.
* adds 's3' package for s3 compatible log storage api, for use with storing
logs from calls and retrieving them.
* removes DELETE /v1/apps/:app/calls/:call/log endpoint
* removes internal log deletion api
* changes the GetLog API to use an io.Reader, which is a backwards step atm
due to the json api for logs, I have another branch lined up to make a plain
text log API and this will be much more efficient (also want to gzip)
* hooked up minio to the test suite and fixed up the test suite
* add how to run minio docs and point fn at it docs
some notes: notably we aren't cleaning up these logs. there is a ticket
already to make a Mr. Clean who wakes up periodically and nukes old stuff, so
am punting any api design around some kind of TTL deletion of logs. there are
a lot of options really for Mr. Clean, we can notably defer to him when apps
are deleted, too, so that app deletion is fast and then Mr. Clean will just
clean them up later (seems like a good option).
have not tested against BMC object store, which has an s3 compatible API. but
in theory it 'just works' (the reason for doing this). in any event, that's
part of the service land to figure out.
closes#481closes#473
* add log not found error to minio land
The Gin middleware is being used if one or more Origins are specified. Default setup for each Origin is as follows:
- GET,POST, PUT, HEAD methods allowed
- Credentials share disabled
- Preflight requests cached for 12 hours
Which are the defaults gin-contrib/cors comes with out of the box.
Gin-cors will return a 403 if it gets a request with an Origin header that isn't on its' list. If no Origin header is specified then it will just return the servers response.
Start fn with CORS enabled:
`API_CORS="http://localhost:4000, http://localhost:3000" make run`
go vet caught some nifty bugs. so fixed those here, and also made it so that
we vet everything from now on since the robots seem to do a better job of
vetting than we have managed to.
also adds gofmt check to circle. could move this to the test.sh script (didn't
want a script calling a script, because $reasons) and it's nice and isolated
in its own little land as it is. side note, changed the script so it runs in
100ms instead of 3s, i think find is a lot faster than go list.
attempted some minor cleanup of various scripts
* idle_timeout max of 1h
* timeout max of 120s for sync, 1h for async
* max memory of 8GB
* do full route validation before call invocation
* ensure that idle_timeout >= timeout
we are now doing validation of updating route inside of the database
transaction, which is what we should have been doing all along really.
we need this behavior to ensure that the idle timeout is longer than the
timeout, among other benefits (like not updating the most recent version of
the existing struct and overwriting previous updates, yay). since we have
this, we can get rid of the weird skipZero behavior on validate too and
validate the real deal holyfield.
validating the route before making the call is handy so that we don't do weird
things like run a func that wants to use 300GB of RAM and run for 3 weeks.
closes#192closes#344closes#162
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're going to want to do this in our service version of this thing, but
adding this here so that it's usable by everyone. just an option, can add it
to server configuration, but response is nicely formatted, etc.
closes#277
cache now implements models.Datastore by just embedding one and then changing
GetApp and GetRoute to have the cache inside. this makes it really flexible
for things like testing, so now the agent doesn't automagically do caching,
now it must be passed a datastore that was wrapped with a cache datastore.
the datastore in the server can remain separate and not use the cache still,
and then now the agent when running fn 'for real' is configured with the cache
baked in. this seems a lot cleaner than what we had and gets the cache out of
the way and it's easier to swap in / out / extend.
* 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)
