Christian Decker 3f3a48dae9 db: Turn the transaction counter into an optimistic lock ... The optimistic lock prevents multiple instances of c-lightning making concurrent modifications to the database. That would be unsafe as it messes up the state in the DB. The optimistic lock is implemented by checking whether a gated update on the previous value of the `data_version` actually results in an update. If that's not the case the DB has been changed under our feet. The lock provides linearizability of DB modifications: if a database is changed under the feet of a running process that process will `abort()`, which from a global point of view is as if it had crashed right after the last successful commit. Any process that also changed the DB must've started between the last successful commit and the unsuccessful one since otherwise its counters would not have matched (which would also have aborted that transaction). So this reduces all the possible timelines to an equivalent where the first process died, and the second process recovered from the DB. This is not that interesting for `sqlite3` where we are also protected via the PID file, but when running on multiple hosts against the same DB, e.g., with `postgres`, this protection becomes important. Changelog-Added: DB: Optimistic logging prevents instances from running concurrently against the same database, providing linear consistency to changes.		2020-01-02 14:12:59 -06:00
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data	pytest: test db upgrade.	2019-09-06 14:19:14 +02:00
plugins	pytest: demonstrate failing rpc_command hook rewrite to plugin.	2019-12-07 21:26:31 +01:00
benchmark.py	py-tests: rename 'announce' to 'wait_for_announce'	2018-12-08 15:15:55 -08:00
conftest.py	pytest: Pass result to fixtures and keep directories of failed tests	2018-08-07 00:54:19 +00:00
db.py	pytest: Have the DB provider search for the postgres binary	2019-09-22 02:03:43 +00:00
fixtures.py	pyln: Allow users to override the LightningNode class	2019-11-12 21:23:55 +01:00
requirements.txt	fix: pip dependency version for psycopg2-binary	2019-12-19 13:26:13 +01:00
test_closing.py	pytest: Skip test_closing_torture under valgrind	2020-01-02 16:05:52 +01:00
test_connection.py	funding: enable push_msat	2019-12-24 12:04:01 -06:00
test_db.py	db: Turn the transaction counter into an optimistic lock	2020-01-02 14:12:59 -06:00
test_gossip.py	Protocol: make var_onion, payment_secret and basic_mpp non-EXPERIMENTAL.	2019-12-12 22:16:03 +01:00
test_invoices.py	pytest: Mark some tests as skippable that are too bitcoin-specific	2019-10-03 04:32:57 +00:00
test_misc.py	pyln: Work around the socket path length on Linux OSs	2020-01-02 16:05:52 +01:00
test_pay.py	channeld: treat all incoming errors as "soft", so we retry.	2019-12-13 16:36:18 +01:00
test_plugin.py	plugin_control: more descriptive key for 'plugin stop' result	2019-12-29 06:44:22 +08:00
test_wallet.py	pytest: Stabilize the hsm_encryption test	2019-12-11 16:18:34 +01:00
utils.py	Protocol: make var_onion, payment_secret and basic_mpp non-EXPERIMENTAL.	2019-12-12 22:16:03 +01:00