featurebase/dax/queryer/client/client.go
Travis Turner 2843f218bc
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
2022-12-05 14:49:17 -06:00

124 lines
3.3 KiB
Go

// Package client is an HTTP client for MDS.
package client
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io"
"net/http"
featurebase "github.com/molecula/featurebase/v3"
"github.com/molecula/featurebase/v3/dax"
queryerhttp "github.com/molecula/featurebase/v3/dax/queryer/http"
"github.com/molecula/featurebase/v3/errors"
"github.com/molecula/featurebase/v3/logger"
)
const (
defaultScheme = "http"
)
// Client is an HTTP client that operates on the MDS endpoints exposed by the
// main MDS service.
type Client struct {
address dax.Address
logger logger.Logger
}
// New returns a new instance of Client.
func New(address dax.Address, logger logger.Logger) *Client {
return &Client{
address: address,
logger: logger,
}
}
// Health returns true if the client address returns status OK at its /health
// endpoint.
func (c *Client) Health() bool {
url := fmt.Sprintf("%s/health", c.address.WithScheme(defaultScheme))
if resp, err := http.Get(url); err != nil {
return false
} else if resp.StatusCode != http.StatusOK {
return false
}
return true
}
func (c *Client) QuerySQL(ctx context.Context, qual dax.TableQualifier, sql string) (*featurebase.WireQueryResponse, error) {
url := fmt.Sprintf("%s/sql", c.address.WithScheme(defaultScheme))
req := &queryerhttp.SQLRequest{
OrganizationID: qual.OrganizationID,
DatabaseID: qual.DatabaseID,
SQL: sql,
}
// Encode the request.
postBody, err := json.Marshal(req)
if err != nil {
return nil, errors.Wrap(err, "marshalling post request")
}
responseBody := bytes.NewBuffer(postBody)
// Post the request.
c.logger.Debugf("POST query sql request: url: %s", url)
resp, err := http.Post(url, "application/json", responseBody)
if err != nil {
return nil, errors.Wrap(err, "posting query sql request")
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
b, _ := io.ReadAll(resp.Body)
return nil, errors.Errorf("status code: %d: %s", resp.StatusCode, b)
}
var wireResp *featurebase.WireQueryResponse
if err := json.NewDecoder(resp.Body).Decode(&wireResp); err != nil {
return nil, errors.Wrap(err, "reading response body")
}
return wireResp, nil
}
func (c *Client) QueryPQL(ctx context.Context, qual dax.TableQualifier, table dax.TableName, pql string) (*featurebase.WireQueryResponse, error) {
url := fmt.Sprintf("%s/query", c.address.WithScheme(defaultScheme))
req := &queryerhttp.QueryRequest{
OrganizationID: qual.OrganizationID,
DatabaseID: qual.DatabaseID,
Table: table,
PQL: pql,
}
// Encode the request.
postBody, err := json.Marshal(req)
if err != nil {
return nil, errors.Wrap(err, "marshalling post request")
}
responseBody := bytes.NewBuffer(postBody)
// Post the request.
c.logger.Debugf("POST query pql request: url: %s", url)
resp, err := http.Post(url, "application/json", responseBody)
if err != nil {
return nil, errors.Wrap(err, "posting query pql request")
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
b, _ := io.ReadAll(resp.Body)
return nil, errors.Errorf("status code: %d: %s", resp.StatusCode, b)
}
var wireResp *featurebase.WireQueryResponse
if err := json.NewDecoder(resp.Body).Decode(&wireResp); err != nil {
return nil, errors.Wrap(err, "reading response body")
}
return wireResp, nil
}