* squash# This is a combination of 10 commits2
fn: get available memory related changes
*) getAvailableMemory() improvements
*) early fail if requested memory too large to meet
*) tracking async and sync pools individually. Sync pool
is reserved for sync jobs only, while async pool can be
used by all jobs.
*) head room estimation for available memory in Linux.
* Update to docs, examples, and tutorial links
* Added categories to docs index page. Removed icons.
* Update to docs, examples, and tutorial links.
Added categories to docs index page. Removed icons.
* updates to docs upon review
* 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
* Docker compose file for simpler dev env
* Updating readme, adding UI to compose
* Define dependencies between services
* Prometheus. Grafana
* Link Prometheus to Grafana service
* Addressing review comments
* Linking compose doc to common table of content
* add error to call model
closes#331
previously, for async this error was being masked completely even if it was
something useful like the image not existing. for sync, the error was returned
in the http request but now it's also being stored. this error itself can
cover a lot of landscape, it could be an error in getting a slot, pulling an
image, running a container, among other things. anyway, no longer being
masked. we can likely improve it in certain cases we run into in the future,
but it's open ended at the moment and not being masked like some errors in
sync http request returns (503 non-models.APIError) for now.
* tucks in callTrigger stuff to keep api clean
* adds swagger
* adds migration
* adds tests for datastore and agent to ensure behavior
* pull images before tests are ran
* gofmt migrations file
* add per call stats field as histogram
this will add a histogram of up to 240 data points of call data, produced
every second, stored at the end of a call invocation in the db. the same
metrics are also still shipped to prometheus (prometheus has the
not-potentially-reduced version). for the API reference, see the updates to
the swagger spec, this is just added onto the get call endpoint.
this does not add any extra db calls and the field for stats in call is a json
blob, which is easily modified to add / omit future fields. this is just
tacked on to the call we're making to InsertCall, and expect this to add very
little overhead; we are bounding the set to be relatively small, planning to
clean out the db of calls periodically, functions will generally be short, and
the same code used at a previous firm did not cause a notable db size increase
with production workload that is worse, wrt histogram size (I checked). the
code changes are really small aside from changing to strfmt.DateTime,
adding a migration and implementing sql.Valuer; needed to slightly modify the
swap function so that we can safely read `call.Stats` field to upload at end.
with the full histogram in hand, we can compute max/min/average/median/growth
rate/bernoulli distributions/whatever very easily in a UI or tooling. in
particular, this data is easily chartable [for a UI], which is beneficial.
* adds swagger spec of api update to calls endpoint
* adds migration for call.stats field
* adds call.stats field to sql queries
* change swapping of hot logger to exec, so we know that call.Stats is no
longer being modified after `exec` [in call.End]
* throws out docker stats between function invocations in hot functions (no
call to store them on, we could change this later for debug; they're in prom)
* tested in tests and API
closes#19
* add format of ints to swag
* fn: introducing 503 responses for out of capacity case
*) Adding 503 with Retry-After header case if request failed
during waiting for slots.
*) TODO: return 503 without Retry-After if the request can
never be met by this fn server.
*) fn: runner test docker pull fixup
*) fn: MaxMemory for routes is now a variable to allow
testing and adjusting it according to fleet memory sizes.
