Questions about server hardware and software performance, or network performance.

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5
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0answers
867 views

Troubleshooting Redmine performance

I've got a Redmine instance (Bitnami Stack) that's unusually slow. Because I'm just trying to get to the bottom of this, I have some theories which I'd like to discuss here. So, if anybody has any ...
4
votes
0answers
186 views

HP MSA P2000 G3 Disk Scrubbing performance?

I have a HP P2000 G3 array with two 10Gbit iSCSI controllers in it that presents storage to my virtualisation cluster. It is soon to be expanded with two D2700 shelves each loaded with 25 10k RPM ...
4
votes
0answers
92 views

Windows Server 2003 terminal server extreme logon times

For the past week my users have been experiencing extreme logon times. They are generally in the 20 minute range or more. I will lay out my research below to see if anyone may know how to find the ...
4
votes
0answers
2k views

Use perfmon to monitor a specific ASP.NET webapp across worker process restarts, IIS restarts, etc.?

I have a few perfmon performance counters that I'd like to track for a specific ASP.NET application over an extended period of time, say a week or a month. The trouble is that perfmon counters are ...
3
votes
0answers
60 views

NGINX Worker Process, Burst Read Speed to only 1918kb/s

I am running an NGINX/1.8 server on Centos6.6 with multiple worker_processes, however while observing iotop I notice they burst up to 1918kb/s Read speed and rarely if at all pass that limit. I want ...
3
votes
0answers
7k views

MySQL Workbench InnoDB Buffer Usage at 100%, always

The InnoDB Buffer Usage graph is always at 100%. I believe this started to happen when I changed MySQL's temp folder to a much bigger drive, does that make sense? I suppose the thing to do in this ...
2
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0answers
14 views

Forking loads disk

I have a prefork/fork daemon. By atop I see, that master-process often consumes disk: PID TID RDDSK WRDSK WCANCL DSK CMD 16830 - 7264K 48696K 18624K 10% our daemon From strace I see, that it ...
2
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0answers
25 views

Finding or estimating sequential vs random distribution of existing system (VMware / SAN)

IOMeter testing says the IOPs of the storage subsystem can range from hundreds of IOPs for 100% random loads to tens of thousands IOPs for 100% sequential loads. Is there any way I can measure or ...
2
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0answers
57 views

Unexpected discrepancy between write and read performance using cryptsetup 1.4.3 and 1.6.6 on Debian Wheezy (7.9) and Debian Jessie (8.2)

I have been setting up a raid1 array and have set up an encrypted medium using cryptsetup with default options. The raid arrays are supposed to use 2 drives, but for the moment, I only have 1 drive in ...
2
votes
0answers
41 views

Google Cloud Long TTFB

Google cloud seems to be having much longer TTFB than they specify in their documentation for cloud storage. You can see from this WPT result that it varies from 500 to 700 MS. The documentation here ...
2
votes
0answers
141 views

Azure ASP.NET website http requests queued

We have a website deployed on Azure that has dreadful performance. When load increases, response times increase to whole minutes! CPU load is not even high, somewhere in the 40% region (we run one ...
2
votes
0answers
172 views

How efficient is the tac command on large files

The taccommand (catreversed) can be used to read a file backwards, just like cat reads it rom the beginning. I wonder, how efficient this is. Does it have to read the whole file from the beginning and ...
2
votes
0answers
397 views

NGINX using 100% of the server CPU when testing with Blitz.io

I'm facing an issue here and after four days of looking around I decided to ask for some help here, after all a million heads can think a lot better than one. I have a Ubuntu 14.04 server setup with ...
2
votes
0answers
1k views

Cannot set 1G speed on 10G nic using ethtool

I have a linux server with 10G fibre nics: xyz@xyz48:~$ sudo ethtool p1p1 Settings for p1p1: Supported ports: [ FIBRE ] Supported link modes: 10000baseT/Full Supported pause frame use: ...
2
votes
0answers
109 views

“Nosy Neighbor” and the CFQ scheduler

I'm trying to understand how does using CFQ affects the "Nosy Neighbor" problem. I'll ask it a bit naively, can a "Nosy Neighbor" even exist when using CFQ? Isn't that CFQ should make sure all ...
2
votes
0answers
787 views

Azure Variable Table v Temp Table

This is a bit long; but I have been working through queries figuring out where a performance issue is coming from. Appreciate you taking the time to read it. I have an application running on a ...
2
votes
0answers
230 views

actual disk iops and write merging

/dev/sdb has LVM and exposes a single logical volume, dm-0. While writing to dm-0, /proc/diskstats reports: # of writes completed sdb 29646717 dm-0 131315099 # of writes merged: sdb 101668283 dm-0 ...
2
votes
0answers
155 views

How to debug sluggish process performance

I have a test application which writes a string to a file 10000 times. I run this on two servers and I get totally different results. [SYSTEM 1] $ time ./test_depth real 0m0.152s user ...
2
votes
0answers
195 views

Infiniband link is at 4X SDR with DDR HCAs; has anyone seen this before?

I've recently upgraded my Infiniband HCAs from SDR to DDR, however upon upgrading, it has not improved the link speed at all. Receiving the following output from 'iblinkinfo': CA: ip-san-1-au3a ...
2
votes
0answers
95 views

IBM xSeries 306 CPU Speed

I have an IBM xSeries 306. The system has been flawless until a week ago. It's a Pentium 4 Dual Core CPU. The CPU speed is 3.20 gHz. Now, it shows 4.26 gHz or 2.16 gHz when the POST screen comes ...
2
votes
0answers
1k views

Amazon RDS: Sudden increase in Read IOPS and Throughput

I am using Amazon RDS to host the databases for my website. I am using the large instances for both my master and my read replica. Everything was running smoothly until suddenly the Read IOPS, Read ...
2
votes
0answers
152 views

IIS 6 About 5% of request are very slow

We have a IIS 6 web server on Win2003 The avg requests/sec = 200 The avg cpu utilization = 30% The memory 10% full HDD avg time = 5% I have turned on the logging to see time-taken for each request ...
2
votes
0answers
121 views

Item count limit in Public Folders?

I'm in the planning phase for a product that is based around an Exchange 2010 (SP2) server, where our items will be stored in public folders. There could be hundreds of thousands of items, and I want ...
2
votes
0answers
157 views

Full Text Search query elapsed time varying wildly

Database Version: Microsoft SQL Server 2005 - 9.00.4035.00 (Intel X86) Nov 24 2008 13:01:59 Copyright (c) 1988-2005 Microsoft Corporation Express Edition with Advanced Services on Windows NT 5.1 ...
2
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0answers
85 views

Benchmarking a file server

I'm working on building a new file server... a simple Windows Server box with a few terabytes of disk space to share on the LAN. Pain for current hard drive prices aside :( -- I would like to get ...
2
votes
0answers
66 views

Text entry out of order during slowness Windows Server 2003 terminal server

When the server is running slowly, anything I type in any text entry box comes in out of order. For example, IPCONFIG might become IPFIGCON. Basically, our Windows Server 2003 R2 x64 Terminal Server ...
2
votes
0answers
893 views

ejabberd benchmarks and performance

I'm considering to use XMPP for messaging platform (not a chat, I'd rather use it as a transport protocol) for communicating one to one, one to many between custom clients and I think I will ...
2
votes
0answers
1k views

How can I improve performance over SMB/CIFS for an application that has poor write speeds?

I have a third party application that reads several large files and generates a third large file. Its performance is quite good when the generated file is stored on "local storage", i.e. either a ...
1
vote
0answers
16 views

rsync: Maximum nice to keep system responsive

Unfortunately a background rsync reduces the responsiveness of a server. I search a way to have maximum niceness for this background task, to keep the server respond fast. My current wrapper ...
1
vote
0answers
18 views

IIS Performance Issues with Flat Files (html, css, js)

We're running an Windows 2012R2 VM with IIS 8.5 with the purpose of serving out flat files, no ASP.NET or other dynamic content is in use. The server is configured to map 5 sites to the same IP & ...
1
vote
0answers
45 views

Improve SSL Performance with Nginx

We have Nginx in the front of our system and we Proxy to Apache at the back. We use SSL/TLS for our connection. Question: Is Nginx the best option to terminate SSL/TLS connections in terms of ...
1
vote
0answers
45 views

Slow gigabit speeds with Ookla speedtest software

We have 2 speedtest servers (RHEL 6.7) sitting on 10GB links with a 10GB pipe between the two. The servers are separated geographically by about 256 miles but traceroutes look very good, with 4 hops ...
1
vote
0answers
20 views

iperf actual send rate always lower than the expected target bandwidth until some equilibrium reached. Why?

I did an UDP iperf 2.0.5-Ubuntu test between two VMs on the same hypervisor. As can be seen in the iperf output below I started my first test with "-b 686M" flag. However, iperf reported that it was ...
1
vote
0answers
10 views

Limiting Oracle instances resources with Cgroups?

Is it possible to limit the amount of resources (I/O, CPU and Memory) a Oracle instance can consume using only cgroups? (no containers or virtualization) The reason I wanna do that is because I want ...
1
vote
0answers
16 views

Performance concern with hosting large clustered DBs on VPS cloud servers

I wonder if anybody else bumped into this issue? You get a couple of beefy 12-core VPS instances in some cloud like DigitalOcean and set up a database on them in "active-passive" cluster ...
1
vote
0answers
30 views

httpd processes cpu spike to 100%+ every xx seconds

My first post, unfortunately due to an issue on my dedicated (Linux Centos 6) server running some personal and one commercial website. Server version: Apache/2.4.18 (Unix) Server built: Mar 7 2016 ...
1
vote
0answers
92 views

What's your experience with the AWS NAT Gateway performance?

In December/2015 Amazon launched their VPC NAT Gateway service which is basically a managed alternative to creating your own (and it looks very good in comparison to NAT instances). I was just about ...
1
vote
0answers
28 views

Persist statistics data from Postgres' stats_temp_directory on demand

We are investigating I/O load in one of our VMs and possibilities to optimize it and it showed that most of the load is generated by the stats collector of PostgreSQL. It jumps between 3,5 and 6,5 ...
1
vote
0answers
71 views

Debug slow lan (ssh, nfs) file transfer

I've got two linux boxes attached to a gigabit switch. They both have gigabit NICs, cables are cat7. Testing the network with iperf shows a fast connection but transferring files with rsync, scp, or ...
1
vote
0answers
98 views

KVM bad IO sync performance in Linux guest

I'm setting up virtualized Ubuntu 15.10 guest inside Ubuntu 15.04 server using libvirt and KVM. Storage in host system: # mount | grep ext4 /dev/sda1 on / type ext4 ...
1
vote
0answers
14 views

Long Response Times for Reads via FCoE

We're getting some intriguing performance with our new FCoE environment, and I was hoping that people could let me know if what we're seeing is expected behaviour. Our switching environment consists ...
1
vote
0answers
210 views

Spring Boot 1.2.7, Tomcat, CSS and Thymeleaf = Very Very slow service

I have a Spring Boot 1.2.7.RELEASE web application (with Tomcat embedded) which needs to handle a very high load spike, ~ 10k connections in 4 to 5 minutes on one server (there is actually a cluster ...
1
vote
0answers
16 views

Trend Smart Scan server updates thrash the disk

Every 2 hours, Trend Worry Free business updates Smart Scan. This process requires Trend to thrash through 6 gigabytes of data - this causes two issues The file cache, full of LOB data, is lost and ...
1
vote
0answers
116 views

MySQL overloading CPU at 100%+

My site appears to be getting over 1 million visits today, usually about 20,000 and for me it seems to be near-unresponsive. I've done some sleuthing and optimised Apache, fixed a bug with PHP ...
1
vote
0answers
29 views

Logrotation performance

One question about logrotation on a dedicated webserver (64gb RAM) with apache and mysql. In high load hours (2k users online every moment) we are experiencing a strange behaviour. As an example, at ...
1
vote
0answers
36 views

xenserver low disk io performance

I have XenServer 6.2 (updates applied XS62E001, XS62E002, XS62E004, XS62E005, XS62E007, XS62E008, XS62E009, XS62E010, XS62E011, XS62E012, XS62E013, XS62E014, XS62ESP1, XS62ESP1002) running a year in ...
1
vote
0answers
48 views

I do a AB Apache Test and it seems good, But when I load my website I get Errors

I have an online shopping website, I use WordPress, WooCommerce and W3 Total Cache. I do a AB: ab -l -r -n 600 -c 30 -k -H "Accept-Encoding: gzip, deflate" And I get the following results: ...
1
vote
0answers
144 views

Performance counter to show real IIS response time

What performance counter should I use to display current average IIS response time? ASP.NET counters correctly show the time spent in ASP.NET, but real latency is much bigger, which is confirmed by ...
1
vote
0answers
144 views

Tuning mdadm RAID 5 performance?

I have a system with dual Intel E5-2620 v3 @ 2.40GHz, 64 GB ram, an LSI 3008 HBA, 8x 1.6 TB Intel S3510 SSDs. I've been playing benchmarking it in different configurations using fio and I've gotten ...
1
vote
0answers
482 views

GlusterFS Split Brain issue

I have been facing issues in performance with GlusterFS setup. We took a new build of application live and suddenly all GlusterFS clients and masters also started showing high utilization of CPU. This ...