Writing to a mutable var is a particularly potent source of leaks since
it mostly defeats GHC's analysis. Here we add assertions to all mutable
writes, and fix a couple spots where we wrote some thunks to a mutable
var (compiled with -O2).
Some of these thunks were probably benign, but others looked liked they
might be retaining big args. Didn't do much analysis, just fixed.
Actually pretty happy with how easy this was to use and as a diagnostic,
once I sorted out some issues. We should consider using it elsewhere,
and maybe extending so that we can use it with tests, enable when
`-fenable-assertsions` etc.
Relates #3388
Also simplified codepaths that use `AcceptWith`, which has unnecessary
`Maybe` fields.
This is the result of a general audit of how we fork threads, with a
detour into how we're using mutable state especially in websocket
codepaths, making more robust to async exceptions and exceptions
resulting from bugs.
Some highlights:
- use a wrapper around 'immortal' so threads that die due to bugs are
restarted, and log the error
- use 'withAsync' some places
- use bracket a few places where we might break invariants
- log some codepaths that represent bugs
- export UnstructuredLog for ad hoc logging (the alternative is we
continue not logging useful stuff)
I had to timebox this. There are a few TODOs I didn't want to address.
And we'll wait until this is merged to attempt #3705 for
Control.Concurrent.Extended
* fix nested insert with returning computed fields gives error, fix#3609
* revert using ordered hashmaps, sort columns based on ordinal postion
* fix 1. keys order 2. json/jsonb column value in nested insert returning
* add a note for sorted columns
* cast 'VALUES' expression as table row type
* use single CTE expression for generating returning for nested inserts
We upload a set of accumulating timers and counters to track service
time for different types of operations, across several dimensions (e.g.
did we hit the plan cache, was a remote involved, etc.)
Also...
Standardize on DiffTime as a standard duration type, and try to use it
consistently.
See discussion here:
https://github.com/hasura/graphql-engine/pull/3584#pullrequestreview-340679369
It should be possible to overwrite that module so the new threadDelay
sticks per the pattern in #3705 blocked on #3558
Rename the Control.Concurrent.Extended.threadDelay to `sleep` since a
naive use with a literal argument would be very bad!
We catch a bug in 'computeTimeDiff'.
Add convenient 'Read' instances to the time unit utility types. Make
'Second' a newtype to support this.
This fixes an issue where queries could incorrectly be considered
reusable if a variable was used in two positions: one where it affected
SQL generation and one where it did not.
* split stm transactions when snapshotting to make it faster
* mx subs: push to both old and new sinks at the same time
* expose dev APIs through allowed APIs flag
* add types to represent unparsed http gql requests
This will help when we add caching of frequently used ASTs
* query plan caching
* move livequery to execute
* add multiplexed module
* session variable can be customised depending on the context
Previously the value was always "current_setting('hasura.user')"
* get rid of typemap requirement in reusable plan
* subscriptions are multiplexed when possible
* use lazytx for introspection to avoid acquiring a pg connection
* refactor to make execute a completely decoupled module
* don't issue a transaction for a query
* don't use current setting for explained sql
* move postgres related types to a different module
* validate variableValues on postgres before multiplexing subs
* don't user current_setting for queries over ws
* plan_cache is only visible when developer flag is enabled
* introduce 'batch size' when multiplexing subscriptions
* bump stackage to 13.16
* fix schema_stitching test case error code
* store hashes instead of actual responses for subscriptions
* internal api to dump subscriptions state
* remove PlanCache from SchemaCacheRef
* allow live query options to be configured on server startup
* capture metrics for multiplexed subscriptions
* more metrics captured for multiplexed subs
* switch to tvar based hashmap for faster snapshotting
* livequery modules do not expose internal details
* fix typo in live query env vars
* switch to hasura's pg-client-hs
