<div dir="ltr"><div><div><div>Quick update for this, I've got some initial numbers on a box with 8x10k RPM SAS disks in RAID5, with 128GiB of RAM:<br><br><table dir="ltr" style="table-layout:fixed;font-size:13px;font-family:arial,sans,sans-serif" cellpadding="0" cellspacing="0">
<colgroup><col width="225"><col width="58"><col width="120"><col width="120"><col width="120"><col width="144"><col width="88"><col width="120"><col width="157"></colgroup><tbody><tr style="height:17px"><td style="vertical-align:bottom;text-align:left;direction:ltr;border-style:solid;border-color:rgb(204,204,204);border-width:1px;font-weight:bold;padding:0px 3px">
msg_store_file_size_limit (MiB)</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:left;direction:ltr;border-bottom:1px solid rgb(204,204,204);font-weight:bold;border-top:1px solid rgb(204,204,204);padding:0px 3px">
queues</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:left;direction:ltr;border-bottom:1px solid rgb(204,204,204);font-weight:bold;border-top:1px solid rgb(204,204,204);padding:0px 3px">
msgs / queue</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:left;direction:ltr;border-bottom:1px solid rgb(204,204,204);font-weight:bold;border-top:1px solid rgb(204,204,204);padding:0px 3px">
msg size (MB)</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:left;direction:ltr;border-bottom:1px solid rgb(204,204,204);font-weight:bold;border-top:1px solid rgb(204,204,204);padding:0px 3px">
total msgs</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:left;direction:ltr;border-bottom:1px solid rgb(204,204,204);font-weight:bold;border-top:1px solid rgb(204,204,204);padding:0px 3px">
total msg size (MB)</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:left;direction:ltr;border-bottom:1px solid rgb(204,204,204);font-weight:bold;border-top:1px solid rgb(204,204,204);padding:0px 3px">
runtime (s)</td><td style="border-right:1px solid rgb(204,204,204);text-align:left;direction:ltr;font-style:normal;font-weight:bold;padding:0px 3px;vertical-align:bottom;font-size:100%;overflow:hidden;white-space:normal;border-bottom:1px solid rgb(204,204,204);font-family:arial,sans,sans-serif;text-decoration:none;border-top:1px solid rgb(204,204,204)">
runtime (s)</td><td style="border-right:1px solid rgb(204,204,204);text-align:left;direction:ltr;font-style:normal;font-weight:bold;padding:0px 3px;vertical-align:bottom;font-size:100%;overflow:hidden;white-space:normal;border-bottom:1px solid rgb(204,204,204);font-family:arial,sans,sans-serif;text-decoration:none;border-top:1px solid rgb(204,204,204)">
avg throughput MB/s</td></tr><tr style="height:17px"><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;direction:ltr;border-bottom:1px solid rgb(204,204,204);padding:0px 3px;border-left:1px solid rgb(204,204,204)">
16</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">100</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
1500</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">1</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
449</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">458</td><td style="border-right:1px solid rgb(204,204,204);text-align:right;font-style:normal;font-weight:normal;padding:0px 3px;vertical-align:bottom;font-size:100%;overflow:hidden;white-space:normal;border-bottom:1px solid rgb(204,204,204);font-family:arial,sans,sans-serif;text-decoration:none">
330.76</td></tr><tr style="height:17px"><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;direction:ltr;border-bottom:1px solid rgb(204,204,204);padding:0px 3px;border-left:1px solid rgb(204,204,204)">
32</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">100</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
1500</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">1</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
425</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">418</td><td style="border-right:1px solid rgb(204,204,204);text-align:right;font-style:normal;font-weight:normal;padding:0px 3px;vertical-align:bottom;font-size:100%;overflow:hidden;white-space:normal;border-bottom:1px solid rgb(204,204,204);font-family:arial,sans,sans-serif;text-decoration:none">
355.87</td></tr><tr style="height:17px"><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;direction:ltr;border-bottom:1px solid rgb(204,204,204);padding:0px 3px;border-left:1px solid rgb(204,204,204)">
64</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">100</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
1500</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">1</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
401</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">400</td><td style="border-right:1px solid rgb(204,204,204);text-align:right;font-style:normal;font-weight:normal;padding:0px 3px;vertical-align:bottom;font-size:100%;overflow:hidden;white-space:normal;border-bottom:1px solid rgb(204,204,204);font-family:arial,sans,sans-serif;text-decoration:none">
374.53</td></tr><tr style="height:17px"><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;direction:ltr;border-bottom:1px solid rgb(204,204,204);padding:0px 3px;border-left:1px solid rgb(204,204,204)">
128</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">100</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
1500</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">1</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
385</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">390</td><td style="border-right:1px solid rgb(204,204,204);text-align:right;font-style:normal;font-weight:normal;padding:0px 3px;vertical-align:bottom;font-size:100%;overflow:hidden;white-space:normal;border-bottom:1px solid rgb(204,204,204);font-family:arial,sans,sans-serif;text-decoration:none">
387.10</td></tr><tr style="height:17px"><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;direction:ltr;border-bottom:1px solid rgb(204,204,204);padding:0px 3px;border-left:1px solid rgb(204,204,204)">
256</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">100</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
1500</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">1</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">150000</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">
383</td><td style="border-right:1px solid rgb(204,204,204);vertical-align:bottom;text-align:right;border-bottom:1px solid rgb(204,204,204);padding:0px 3px">385</td><td style="border-right:1px solid rgb(204,204,204);text-align:right;font-style:normal;font-weight:normal;padding:0px 3px;vertical-align:bottom;font-size:100%;overflow:hidden;white-space:normal;border-bottom:1px solid rgb(204,204,204);font-family:arial,sans,sans-serif;text-decoration:none">
390.63</td></tr></tbody></table><br></div>I get some reasonable gains by bumping msg_store_file_size_limit up to 128 MiB, 256 MiB seems to be only marginal returns. This may simply be because it can't batch up more data than that in RAM prior to writing, given the RAM in my test system. Note that the underlying FS itself is capable of delivering 780MB/s in block writes, so this is still less than I expected to see, but demonstrates there's some minor advantages to be had by using larger store sizes.<br>
<br></div>My next theory was that 100 queues would mean a minimum of 100 on disk persistent files, and that I'd see better block throughput with less queues and more messages. However, testing with lower numbers of queues and higher messages per queue (to keep total messages delivered constant) revealed some weird behaviour:<br>
<br><style type="text/css"><!-- br {mso-data-placement:same-cell;} --></style><table dir="ltr" style="table-layout:fixed;font-size:13px;font-family:arial,sans,sans-serif" cellpadding="0" cellspacing="0"><colgroup><col width="225"><col width="58"><col width="120"><col width="120"><col width="120"><col width="144"><col width="88"><col width="120"><col width="157"></colgroup><tbody><tr style="height:17px">
<td style="padding:0px 3px;vertical-align:bottom;direction:ltr;color:rgb(0,0,0);text-align:left;font-weight:bold;border-width:1px;border-style:solid;border-color:rgb(204,204,204)">msg_store_file_size_limit (MiB)</td><td style="padding:0px 3px;vertical-align:bottom;font-weight:bold;direction:ltr;color:rgb(0,0,0);text-align:left;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-top:1px solid rgb(204,204,204)">
queues</td><td style="padding:0px 3px;vertical-align:bottom;font-weight:bold;direction:ltr;color:rgb(0,0,0);text-align:left;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-top:1px solid rgb(204,204,204)">
msgs / queue</td><td style="padding:0px 3px;vertical-align:bottom;font-weight:bold;direction:ltr;color:rgb(0,0,0);text-align:left;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-top:1px solid rgb(204,204,204)">
msg size (MB)</td><td style="padding:0px 3px;vertical-align:bottom;font-weight:bold;direction:ltr;color:rgb(0,0,0);text-align:left;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-top:1px solid rgb(204,204,204)">
total msgs</td><td style="padding:0px 3px;vertical-align:bottom;font-weight:bold;direction:ltr;color:rgb(0,0,0);text-align:left;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-top:1px solid rgb(204,204,204)">
total msg size (MB)</td><td style="padding:0px 3px;vertical-align:bottom;font-weight:bold;direction:ltr;color:rgb(0,0,0);text-align:left;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-top:1px solid rgb(204,204,204)">
runtime (s)</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:bold;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);direction:ltr;color:rgb(0,0,0);text-align:left;border-top:1px solid rgb(204,204,204)">
runtime (s)</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:bold;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);direction:ltr;color:rgb(0,0,0);text-align:left;border-top:1px solid rgb(204,204,204)">
avg throughput MB/s</td></tr><tr style="height:17px"><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right;border-left:1px solid rgb(204,204,204)">
128</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
100</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
1500</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
1</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
150000</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
150000</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
385</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
390</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
387.10</td></tr><tr style="height:17px"><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-left:1px solid rgb(204,204,204)">
128</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">50</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
3000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">1</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
150000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">150000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
373</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
376</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
400.53</td></tr><tr style="height:17px"><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-left:1px solid rgb(204,204,204)">
128</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">25</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
6000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">1</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
150000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">150000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
409</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
413</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
364.96</td></tr><tr style="height:17px"><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-left:1px solid rgb(204,204,204)">
128</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">10</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
15000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">1</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
150000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">150000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
463</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
442</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
331.49</td></tr><tr style="height:17px"><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204);border-left:1px solid rgb(204,204,204)">
128</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">5</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
30000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">1</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
150000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">150000</td><td style="padding:0px 3px;vertical-align:bottom;color:rgb(0,0,0);text-align:right;border-bottom:1px solid rgb(204,204,204);border-right:1px solid rgb(204,204,204)">
465</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
448</td><td style="padding:0px 3px;background-color:white;font-family:arial,sans,sans-serif;font-size:100%;font-weight:normal;font-style:normal;text-decoration:none;vertical-align:bottom;white-space:normal;overflow:hidden;border-right:1px solid rgb(204,204,204);border-bottom:1px solid rgb(204,204,204);color:rgb(0,0,0);text-align:right">
328.59</td></tr></tbody></table><br></div><div>Looks like queue contention becomes a bigger bottleneck than IO throughput once you get below 50 queues, which is a result I didn't expect. In any case, looks like max storage size ~= RAM hits some sort of buffering/contention sweet spot, at least with larger messages, so that's something which should be easy enough to automate.<br>
<br></div><div>Graeme<br><br></div><div><br></div><div><div><div><div></div></div></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, Nov 20, 2013 at 2:01 PM, Graeme N <span dir="ltr"><<a href="mailto:graeme@sudo.ca" target="_blank">graeme@sudo.ca</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote"><div class="im">On Wed, Nov 20, 2013 at 12:56 PM, Matthias Radestock <span dir="ltr"><<a href="mailto:matthias@rabbitmq.com" target="_blank">matthias@rabbitmq.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">The msg_store has a gc hat has a hard upper bound on the amount of<br>
garbage left around. See the essay near the beginning of<br>
<a href="http://hg.rabbitmq.com/rabbitmq-server/file/default/src/rabbit_msg_store.erl" target="_blank">http://hg.rabbitmq.com/rabbitmq-server/file/default/src/rabbit_msg_store.erl</a> for the gory details.<br></blockquote>
</div><div><br>This is extremely informative. Definitely helping me get a better understanding of what Rabbit's IO patterns are. Thanks!<span class="HOEnZb"><font color="#888888"><br><br>Graeme<br></font></span></div>
</div></div></div>
</blockquote></div><br></div>