Kim van der Riet created QPID-7666:
--------------------------------------
Summary: [linearstore] Enhancements to the write buffer default
and per-queue options
Key: QPID-7666
URL: https://issues.apache.org/jira/browse/QPID-7666
Project: Qpid
Issue Type: Improvement
Components: C++ Broker
Affects Versions: qpid-cpp-1.37.0
Reporter: Kim van der Riet
Assignee: Kim van der Riet
In applications where large numbers of persistent queues are created on a
single broker, control over the default and per-queue store options are
important so that resources are not wasted or become exhausted prematurely.
There are two resources of concern:
# Memory allocated per queue for buffering;
# Disk resources consumed for journal files.
Currently, the default setting for memory allocation is 1024kiB/queue (ie 32
pages of 32kiB). The only default setting available is the page size (using the
{{wcache-page-size}} option), and the number of pages is set internally
according to the following table:
||{{wcache-page-size}}||{{wcache-num-pages}}||total mmap||
||(kiB)||(set interanlly)||(kiB)||
| 4 | 64 | 256 |
| 8 | 64 | 512|
| 16 | 32 | 512|
| 32* | 32 | 1024|
| 64 | 16 | 1024|
|128 | 8 | 1024|
\* default
This gives in effect only 3 per-queue memory allocation options: 256kiB, 512kiB
and 1024kiB.
Currently, the values of {{wcache-page-size}} is limited to the powers of 2
between 4 and 128.
It is suggested that the {{wcache-num-pages}} value be set as as an option
rather than internally, which would give the user much greater control over the
per-queue memory footprint and the buffer geometry (which can be optimized for
the disk hardware and queue load characteristics).
In addition, the upper value limit on {{wcache-page-size}} should be removed
(as it is rather arbitrary) and the default value should be revised.
Further, it would be valuable to add these parameters to {{qpid-config}} so
that if a queue is created using this tool, the default values for the store
parameters can be overridden on a per-queue basis.
Disk resource controls are currently in place for the EFP partition
({{efp-partition}}) and the size of the EFP files ({{efp-file-size}}), both as
a default and in {{qpid-config}}. The default values should also be revised.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
