[jira] [Updated] (BEAM-170) Session windows should not be identified by their bounds
[ https://issues.apache.org/jira/browse/BEAM-170?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Davor Bonaci updated BEAM-170: -- Fix Version/s: (was: First stable release) > Session windows should not be identified by their bounds > > > Key: BEAM-170 > URL: https://issues.apache.org/jira/browse/BEAM-170 > Project: Beam > Issue Type: Bug > Components: sdk-java-core >Reporter: Kenneth Knowles >Assignee: Kenneth Knowles > Labels: backward-incompatible > > Today, if two session windows for the same key have the same bounds, they are > considered the same window. This is an accident. It is not intended that any > session windows are considered equal except via the operation of merging them > into the same session. > A risk associated with this behavior is that two windows that happen to > coincide will share per-window-and-key state rather than evolving separately > and having their separate state reconciled by state merging logic. These code > paths are not required to be coherent, and in practice they are not. > In particular, if the trigger for a session window ever finishes, then > subsequent data in a window with the same bounds will be dropped, whereas if > it had differed by a millisecond it would have created a new session, > ignoring the previously closed session. -- This message was sent by Atlassian JIRA (v6.3.15#6346)
[jira] [Updated] (BEAM-170) Session windows should not be identified by their bounds
[ https://issues.apache.org/jira/browse/BEAM-170?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Kenneth Knowles updated BEAM-170: - Fix Version/s: First stable release > Session windows should not be identified by their bounds > > > Key: BEAM-170 > URL: https://issues.apache.org/jira/browse/BEAM-170 > Project: Beam > Issue Type: Bug > Components: sdk-java-core >Reporter: Kenneth Knowles >Assignee: Ilya Ganelin > Labels: backward-incompatible > Fix For: First stable release > > > Today, if two session windows for the same key have the same bounds, they are > considered the same window. This is an accident. It is not intended that any > session windows are considered equal except via the operation of merging them > into the same session. > A risk associated with this behavior is that two windows that happen to > coincide will share per-window-and-key state rather than evolving separately > and having their separate state reconciled by state merging logic. These code > paths are not required to be coherent, and in practice they are not. > In particular, if the trigger for a session window ever finishes, then > subsequent data in a window with the same bounds will be dropped, whereas if > it had differed by a millisecond it would have created a new session, > ignoring the previously closed session. -- This message was sent by Atlassian JIRA (v6.3.15#6346)
