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Diffstat (limited to 'doc/build')
| -rw-r--r-- | doc/build/changelog/unreleased_20/5648.rst | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/doc/build/changelog/unreleased_20/5648.rst b/doc/build/changelog/unreleased_20/5648.rst new file mode 100644 index 000000000..acc1251b1 --- /dev/null +++ b/doc/build/changelog/unreleased_20/5648.rst @@ -0,0 +1,24 @@ +.. change:: + :tags: bug, mysql, postgresql + :tickets: 5648 + + The support for pool ping listeners to receive exception events via the + :meth:`.ConnectionEvents.handle_error` event added in 2.0.0b1 for + :ticket:`5648` failed to take into account dialect-specific ping routines + such as that of MySQL and PostgreSQL. The dialect feature has been reworked + so that all dialects participate within event handling. Additionally, + a new boolean element :attr:`.ExceptionContext.is_pre_ping` is added + which identifies if this operation is occurring within the pre-ping + operation. + + For this release, third party dialects which implement a custom + :meth:`_engine.Dialect.do_ping` method can opt in to the newly improved + behavior by having their method no longer catch exceptions or check + exceptions for "is_disconnect", instead just propagating all exceptions + outwards. Checking the exception for "is_disconnect" is now done by an + enclosing method on the default dialect, which ensures that the event hook + is invoked for all exception scenarios before testing the exception as a + "disconnect" exception. If an existing ``do_ping()`` method continues to + catch exceptions and check "is_disconnect", it will continue to work as it + did previously, but ``handle_error`` hooks will not have access to the + exception if it isn't propagated outwards. |