https://github.com/kelvich/pg_tsdtm
https://github.com/kelvich/pg_tsdtm
Last synced: 2 months ago
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- Host: GitHub
- URL: https://github.com/kelvich/pg_tsdtm
- Owner: kelvich
- Created: 2015-11-05T23:53:53.000Z (over 9 years ago)
- Default Branch: master
- Last Pushed: 2015-11-05T23:57:00.000Z (over 9 years ago)
- Last Synced: 2025-03-23T18:54:17.103Z (3 months ago)
- Language: Go
- Size: 0 Bytes
- Stars: 3
- Watchers: 1
- Forks: 6
- Open Issues: 0
-
Metadata Files:
- Readme: README
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README
===
dtm
===
Distributed transaction management tools for PostgreSQL.
--------------------
Communication scheme
--------------------
.- Backend -.
/ \
/ \
DTM ---- Backend ---- Coordinator
\ /
\ /
`- Backend -´
-----------------------
Coordinator-Backend API
-----------------------
This API includes a set of postgres procedures that
the coordinator can call with "select" statement.
extend_transaction (n integer) -> (higcid gcid)
join_transaction (higcid gcid) -> ()
FIXME: add procedures that would start and finish 2pc
----------
libdtm api
----------
typedef unsigned long long cid_t;
// Connects to the specified DTM.
DTMConn DtmConnect(char *host, int port);
// Disconnects from the DTM. Do not use the 'dtm' pointer after this call, or
// bad things will happen.
void DtmDisconnect(DTMConn dtm);
// Asks DTM for the first 'gcid' with unknown status. This 'gcid' is used as a
// kind of snapshot. Returns the 'gcid' on success, or INVALID_GCID otherwise.
cid_t DtmGlobalGetNextCid(DTMConn dtm);
// Prepares a commit. Returns the 'gcid' on success, or INVALID_GCID otherwise.
cid_t DtmGlobalPrepare(DTMConn dtm);
// Finishes a given commit with 'committed' status. Returns 'true' on success,
// 'false' otherwise.
bool DtmGlobalCommit(DTMConn dtm, cid_t gcid);
// Finishes a given commit with 'aborted' status.
void DtmGlobalRollback(DTMConn dtm, cid_t gcid);
// Gets the status of the commit identified by 'gcid'. Returns the status on
// success, or -1 otherwise.
int DtmGlobalGetTransStatus(DTMConn dtm, cid_t gcid);
--------------------
Backend-DTM Protocol
--------------------
DTM <--> Backend:
<- 'p' - "prepare"
-> '+' - "commit prepared"
-> '-' - "something went wrong"
<- 'c' - "commit"
-> '+' - "commit saved"
-> '-' - "something went wrong"
<- 'a' - "abort"
-> '+' - "abort saved"
-> '-' - "something went wrong"
<- 'h' - "horizon"
-> '+' - "here is a gcid you can use as a snapshot"
-> '-' - "something went wrong"
<- 's' - "status"
-> '+''c|a|?' - "here is the transaction status"
(c)ommitted, (a)borted or (?)unknown
-> '-' - "something went wrong"
Backend disconnection is considered as an abort of all incomplete commits
prepared by that backend.