[QPID-5533] [C++ broker] Linearstore to return any empty page to EPL

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 0.24
• Component/s: C++ Broker
• Assignee: Unassigned
• Reporter: Pavel Moravec
• Created: 01/Feb/14 15:14
• Updated: 01/Feb/14 15:14

Description

Linear store should return to EPL any empty file of a journal, not only the oldest one (once it gets emptied). As there can be corner cases where journal enqueue record sits in journal (almost) forever, while the journal gets next enqueue+dequeue records in parallel. In particular, basic scenarios cover message filters in consumers, priority queue (with message of lower priority never consumed), or tpl journal with orphaned transaction (until QPID-5531 is fixed).

One particular reproducer with priority queue:

qpid-config add queue testQueue --argument=x-qpid-priorities=10 --durable
qpid-send -a testQueue -m 1 --priority 1 --durable=yes
while true; do ./src/tests/qpid-send -a testQueue -m 5000 --priority 2 --durable=yes; ./src/tests/qpid-receive -a testQueue -m 5000 --print-content=no; qpid-stat -q; done

~/.qpidd/qls/jrnl/testQueue/ grows forever.

(I am fine to close it as WONTFIX if a potential fix would be too complex, compared to the probability of the corner cases)