27 releases
Uses old Rust 2015
0.8.6 | Dec 16, 2018 |
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0.8.5 | Jun 22, 2017 |
0.8.3 | May 1, 2017 |
0.5.1 | Mar 30, 2017 |
0.3.1 | Dec 31, 2016 |
#2606 in Database interfaces
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70KB
866 lines
pg_async.rs
Asynchronous, HA (master-master) PostgreSQL driver on top of libpq.
Vision
- Designed to work with a master-master replicated database, such as BDR (but standalone databases are supported too).
- Uses
libpq
, leveraging it's asynchronous support. - Maintains an asynchronous connection to every node of the replicated cluster.
- Pings the nodes (with
SELECT 1
) to see who's closer/faster. - Every operation is a separate transaction.
- If a node fails, the operation is transparently retried on another node.
- Operations are exposed as
futures
. -
futures
are backed by a thread or two and can be used without atokio
reactor (because KISS). - Fast mode: send the operation to every node and return the first answer.
- Pin mode: send the operation to one of the nodes only (useful to avoid some of the master-master conflicts).
- There is a JSON helper converting table rows to serde_json objects.
- If the operation wasn't pipelined already, dropping a
Future
allows the driver to cancel it. - Database-level timeouts can be used to terminate slow operations early.
Notes
The combination of libpq and OpenSSL doesn't work very well during PostgreSQL server restarts. I've seen libpq SEGV-crash reliably when the OpenSSL layer is enabled. For the driver to properly work around PostgreSQL server unavailability and restarts I recommend adding the "sslmode=disable" disabler to the connection strings.
Dependencies
~5MB
~100K SLoC