1.3 Tasks

###Distributed Index/sg_accel

####Refactor repo to not hijack GOPATH

• Use GO15VENDOREXPERIMENT=1 instead of submodules
• Buildable by standard Go tools like go get github.com/couchbase/sync_gateway
• All packages would live in standard GOPATH

####Decoupling sg_accel from Sync Gateway

• Move sg_accel to it's own repo.
• Move common code used by index readers and writers to a new library/repo, and refactor SG and sg_accel to use.
• Pull all index writer functionality out of sync gateway.
• Define administration API for sg_accel, and remove the rest of the SG REST API from sg_accel.

####Performance

• Modify index storage to better handle scenarios with a large number of sparse channels.
• Non-mini matrix performance testing:
  • Full suite of scenarios.
  • Varying number of channels, num_shards, doc size, etc.
  • Additional performance analysis/fixes to significantly increase SG per-node throughput.
• Index compaction. (https://github.com/couchbase/sync_gateway/issues/1030)
• Convert cb-heartbeat to not require a view. (https://github.com/couchbase/sync_gateway/issues/1217)
• Fix out-of-memory issues under load. (https://github.com/couchbase/sync_gateway/issues/1514)
• Improve change detection performance. Current polling has decent performance degradation as the number of channels/users per reader node increases. Possibly a two-phase approach:
  • Improve the current polling approach (hotfix)
  • Replace polling with something like projector (GA)

####Reliability

• Fix issues during DCP restart (OpaqueSet issue) - https://github.com/couchbase/sync_gateway/issues/1371
• Handling for data bucket rollback
  • Rollback for data that hasn't yet been indexed
  • Rollback for data that has been indexed (https://github.com/couchbase/sync_gateway/issues/1211)
• Handling for index bucket rollback
• Identifying unhealthy index (https://github.com/couchbase/sync_gateway/issues/1133)

####Correctness

• Channel removal notification and coalesced DCP updates (https://github.com/couchbase/sync_gateway/issues/1227)
• last_seq value for empty responses (https://github.com/couchbase/sync_gateway/issues/1529)
• Support _doc_ids filter when using distributed index (https://github.com/couchbase/sync_gateway/issues/1316)

####Usability and Administration

• Resync without manual flush of index bucket (https://github.com/couchbase/sync_gateway/issues/1107)
• sg_accel admin UI (including CBGT UI - https://github.com/couchbase/sync_gateway/issues/1152)
• REST api endpoints to give visibility into channel index (https://github.com/couchbase/sync_gateway/issues/1457)

##Non-DI

###General Functionality

• Bring DCP to GA quality (https://github.com/couchbase/sync_gateway/issues/1406)