featurebase/dax/queryer/service/queryer.go
Travis Turner a44b622aa0 Introduce ServiceManager and Refactor DAX Integration tests (#2320)
* Introduce ServiceManager and Refactor DAX Integration tests

The ServiceManager provides an interface with which to manage
featurebase (dax) services (mds, queryer, computer). It replaces the
confusing interface implementations in /dax/server/server.go (which
optionally used pointers to in-process objects to satisfy an interface)
with (for now) http implementations. The thought is that even if we're
running all services in-process, we should communicate between services
over http in order to mirror what we would do in a production
environment where the services are running on different nodes.

This batch of commits does quit a lot, most of which is captured here:

- Added `path` support to `dax.Address`. Address is now a string of the form [scheme]://[host]:[port]/[path].
- Added `Holder.directiveApplied` to determine (in tests) if the computer has completed applying the latest directive. This is somewhat temporary until we improve the mds-to-computer logic.
- Removed the "service prefix" code which was prepending client URL paths with the prefix. Instead, the serviceType (mds, queryer, computer[n] is now part of `dax.Address`).
- Removed, from the dax config, the top level `StorageMethod` and `StorageDSN` and now just have `MDS.Config.DataDir`.
- Added `Computer.Config.N` to specify the number of computers to run in-process.
- Moved the `pilosa.MDS` interface to `computer.Registrar`. This is an example of getting the interfaces defined in the right packages.
- Added `SnapshotTable()` method to the mds client (to align with its API).
- Changed `Balancer.AddJob()` to `Balancer.AddJobs()` to support, for example, adding 256 partitions in a single call. Refactored some of the naive Balancer to account for this.
- Added a `Seed` to the top-level config. It's not really useful because of package `crypto/rand`.
- Added an in-memory implementation of the DisCo interface and disabled etcd in a computer service.
- Create sepearte data-dirs for each in-process computer.
- Disabled grpc in dax.
- Modified the sql3 test definition format to support multiple insert steps and separate query results (to align with those steps).

* Changes necessary to get multiple computer instance running in-process

For now the config looks like this:

```
[computer]
run = true
n = 4
```

but we can probably just change that to be something like:

```
[computer]
run = 4
```

*Issues found running multiple "computers" in-process*
- grpc was trying to bind on the same port
  - changed GRPCListener from `*net.TCPListener` to `net.Listener`
  - created a nopListener and set to that for now (i.e. disabled grpc)
- etcd was starting more than once
  - changed dax to use in-memory implementations of the disco interfaces (i.e. stop using etcd)
- IDAllocator (which uses boltdb) was trying to open the `idalloc.db` file more than once
  - realized we have to set separate data-dirs for each holder. that fixed it.

* Port dax integration tests to ManagedCommand

* Modify Balancer-related methods like AddJob to AddJobs

There were (and still are) a lot of places where we were adding on job
at a time, even when we had a long list of jobs to add. This resulted in
every job add (for example adding 1 of 256 shards) taking ~40ms, or over
10s to create a keyed table. One reason was because each job add was
making multiple boltdb transactions.

* Port over more dax integration test stuff

* Add DirectiveApplied to signify that snapshot/writes have loaded.

We use this in tests to avoid using sleeps.
This should be considered temporary; we're going to need a more robust
solution for determining when a computer node is ready to serve complete
data.

* Finish porting dax integration tests

* Improve godocs

* Remove docker-based DAX integration tests.

* go mod tidy

* Move test/managed.go to avoid package conflicts

* Modify IDK integration tests to work with ServiceManager changes

This is really just computer -> computer0
And the MDS DataDir config change.

* cleanup found during review

* echo $CI_COMMIT_REF_SLUG in CI

* remove docker image arg, use build instead

(cherry picked from commit 2843f218bc)
2022-12-12 09:01:20 -08:00

55 lines
1.3 KiB
Go

package service
import (
"net/http"
"github.com/molecula/featurebase/v3/dax"
mdsclient "github.com/molecula/featurebase/v3/dax/mds/client"
"github.com/molecula/featurebase/v3/dax/queryer"
queryerhttp "github.com/molecula/featurebase/v3/dax/queryer/http"
"github.com/molecula/featurebase/v3/errors"
"github.com/molecula/featurebase/v3/logger"
fbnet "github.com/molecula/featurebase/v3/net"
)
// Ensure type implements interface.
var _ dax.Service = (*queryerService)(nil)
type queryerService struct {
uri *fbnet.URI
queryer *queryer.Queryer
logger logger.Logger
}
func New(uri *fbnet.URI, queryer *queryer.Queryer, logger logger.Logger) *queryerService {
return &queryerService{
uri: uri,
queryer: queryer,
logger: logger,
}
}
func (q *queryerService) Start() error {
// Start queryer service.
if err := q.queryer.Start(); err != nil {
return errors.Wrap(err, "starting queryer")
}
return nil
}
func (q *queryerService) Stop() error {
return nil
}
func (q *queryerService) Address() dax.Address {
return dax.Address(q.uri.HostPort() + "/" + dax.ServicePrefixQueryer)
}
func (q *queryerService) HTTPHandler() http.Handler {
return queryerhttp.Handler(q.queryer)
}
func (q *queryerService) SetMDS(addr dax.Address) error {
q.queryer.SetMDS(mdsclient.New(addr, q.logger))
return nil
}