<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">
<div>
<div>
<div>
<p style="color: rgb(34, 34, 34); margin: 5px 0px 0px; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: 18px; widows: 1;">
<font face="Helvetica">I'm experimenting with moving some of our more heavily used files (about 5% of the file system) from disk to a flash tier. The disk latency is around 10ms, while the flash is less than 1ms. What I'm seeing that when I move the files to
flash, my NSD server queues (thread queues) have a much larger number of pending RPCs. (on the Small queues) Not surprising, since the storage subsystem is faster, the clients push more requests and the NSD server backs up. I don't see an evidence of the NSD
server itself running out of steam (CPU below 20%) so I'm thinking I just need to adjust the number of threads and the threads per queue. Right now I have this:</font></p>
<p style="color: rgb(34, 34, 34); margin: 5px 0px 0px; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: 18px; widows: 1;">
<font face="Helvetica"><br>
</font></p>
<p class="p1" style="color: rgb(34, 34, 34); font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; margin: 5px 0px 0px; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: 18px; widows: 1;">
<span style="font-family: 'courier new', courier, monospace;">nsdMaxWorkerThreads=256, nsdMinWorkerThreads=256, nsdThreadsPerQueue=8, nsdSmallThreadRatio=1</span></p>
<p class="p1" style="color: rgb(34, 34, 34); font-size: 12px; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; margin: 5px 0px 0px; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: 18px; widows: 1;">
<span style="font-family: 'courier new', courier, monospace;"><br>
</span></p>
<p class="p1" style="color: rgb(34, 34, 34); margin: 5px 0px 0px; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: 18px; widows: 1;">
<font face="Helvetica"><span class="s1">What I'm trying to decide is whether I should increase just the MaxThreads or both the MaxThreads and the ThredsPerQueue.</span><br>
</font></p>
<p class="p1" style="margin: 5px 0px 0px; font-variant-ligatures: normal; font-variant-position: normal; font-variant-numeric: normal; font-variant-alternates: normal; font-variant-east-asian: normal; line-height: 18px; widows: 1;">
<font face="Helvetica"><span class="s1"><font color="#222222">Can anyone offer advice? I did read through Yuri’s document.</font></span><br>
</font></p>
</div>
<div style="color: rgb(0, 0, 0); font-size: 14px; font-family: Helvetica, sans-serif;">
<span class="s1"><br>
</span></div>
<div style="color: rgb(0, 0, 0); font-size: 14px; font-family: Helvetica, sans-serif;">
<div id="">
<div style="color: rgb(0, 0, 0); font-family: Calibri, sans-serif; font-size: 14px;">
<span style="font-family: Calibri; font-size: medium;"><br>
</span></div>
<div style="color: rgb(0, 0, 0); font-family: Helvetica, sans-serif; font-size: 14px;">
<font face="Helvetica">Bob Oesterlin<br>
Sr Storage Engineer, Nuance HPC Grid<br>
</font></div>
</div>
</div>
</div>
</div>
</body>
</html>