Move mutations out

[manishrjain]

• Query no longer contains mutations. This means:
  • No more query vars can be used in mutations.
  • No more upserts. They will be done via transactions.
  • Gql doesn't need to parse for mutations or schema mutations.
• Add a new endpoint called Mutate, just for mutations.
• Remove http endpoint /query. All read-write ops must be done via a grpc client.

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This change is 

[pawanrawal]

Apart from this a lot of upsert code can be removed from worker/scheduler.go too. Once you merge I can remove that, should be quicker that way.

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Review status: 0 of 16 files reviewed at latest revision, 2 unresolved discussions.

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dgraph/server.go, line 215 at r1 (raw file):

		Str:       req.Query,
		Variables: req.Vars,
		Http:      false,

this flag can be removed as well as http is always false now. Maybe add a TODO for later.

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dgraph/server.go, line 341 at r1 (raw file):

		}

		// TODO: Sort the facets by key.

We saw that this is being done later, so TODO can be removed.

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Comments from Reviewable

[manishrjain]

Awesome. Will let you delete the upsert code in the scheduler.

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Review status: 0 of 16 files reviewed at latest revision, 2 unresolved discussions.

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dgraph/server.go, line 215 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

this flag can be removed as well as http is always false now. Maybe add a TODO for later.

Done. Added a TODO for now.

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dgraph/server.go, line 341 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

We saw that this is being done later, so TODO can be removed.

Done.

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Comments from Reviewable

[manishrjain]

Pushed to master at 06d576b. This would break tests and would make the code unstable for a bit while we're working on transactions and making major changes throughout the code base.