Two-phase (2PC) and three-phase (3PC) protocols implementaion in Golang. Committer uses BadgerDB for persistence.
protocols description:
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http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.63.7048&rep=rep1&type=pdf (2PC)
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http://courses.cs.vt.edu/~cs5204/fall00/distributedDBMS/sreenu/3pc.html (3PC)
Configuring
All config parameters may be specified via command-line flags
| flag | description | default | example |
|---|---|---|---|
| role | role of the node (coordinator of follower) | follower | -role=coordinator |
| nodeaddr | node address | localhost:3050 | -nodeaddr=localhost:3051 |
| coordinator | coordinator address | "" | -coordinator=localhost:3050 |
| committype | two-phase or three-phase commit mode | three-phase | -committype=two-phase |
| timeout | timeout after which the message is considered unacknowledged (only for three-phase mode, because two-phase is blocking by design) | 1000 | -timeout=500 |
| dbpath | database path on filesystem | ./badger | -dbpath=/tmp/badger |
| followers | comma-separated list of followers' addresses | "" | -followers=localhost:3052,localhost:3053,localhost:3053 |
| whitelist | comma-separated list of allowed hosts | 127.0.0.1 | -whitelist=192.168.0.105,192.168.0.101 |
example follower:
./committer -role=follower -nodeaddr=localhost:3001 -committype=three-phase -timeout=1000 -dbpath=/tmp/badger/follower
example coordinator:
./committer -role=coordinator -nodeaddr=localhost:3000 -followers=localhost:3001 -committype=three-phase -timeout=1000 -dbpath=/tmp/badger/coordinator
Hooks
Hooks for requests checking on Propose and Commit stage. It's just a function that receives *pb.ProposeRequest or *pb.CommitRequest and returns true or false. Function body incorporate all validation logic.
Example hooks can be found at core/cohort/commitalgo/hooks/hooks.go.
You can replace code in the core/cohort/commitalgo/hooks/hooks.go file used by committer to inject your validation logic into the handlers.
Testing
functional tests: make tests
Testing with example client
compile executables:
make prepare
run coordinator:
make run-example-coordinator
run follower in another shell:
make run-example-follower
run example client:
go run ./examples/client/client.go
Planned Implement a flexible transaction log mechanism. Current in-mem implementation is not reliable.