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

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5
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0answers
840 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
136 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
90 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
54 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 ...
2
votes
0answers
46 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
32 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
111 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
370 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
914 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
104 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
693 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
6k 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
votes
0answers
193 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
148 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
186 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
92 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
966 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
138 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
111 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
156 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
votes
0answers
82 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
869 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
46 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
18 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
17 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
52 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
155 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
13 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
94 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
23 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
30 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
41 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
121 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
359 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 ...
1
vote
0answers
111 views

LSI SAS1068E (aka LSI SAS 3442E-R) bandwidth

Recently I connected LSI SAS 3442E-R and two HP SAS 600GB 10k HDD. My motherboard is AsRock Z97 Extreme6. Disk are configured as JBOD, no raid. Linux lspci shows: 0b:00.0 SCSI storage controller: ...
1
vote
0answers
82 views

Redis parent process smashing disk despite appendfsync = no

We are seeing loads of IO from redis-server despite our save operations being set to occur once every 15 minutes only. The workload is a "full page cache"; we store blobs of compressed HTML. The HTML ...
1
vote
0answers
196 views

VMWare ESXi and iSCSI via FreeNAS

I've recently been setting up a sandbox ESXi environment with a VM running FreeNAS providing a volume which is connected as a datastore on the host via iSCSI. I've created a VM on this datastore and ...
1
vote
0answers
142 views

100% CPU, load average 0 - how is this possible?

Here's the top output: top - 19:20:47 up 1 day, 4:30, 1 user, load average: 0.01, 0.07, 0.12 Tasks: 170 total, 1 running, 169 sleeping, 0 stopped, 0 zombie %Cpu(s): 0.6 us, 0.9 sy, 0.0 ...
1
vote
0answers
19 views

Force disk cache even if guest uses direct i/o

Have IBM db2 on Rhel on Hyper-V on Windows Server. The *.vhdx file is on CSV. e.g. C:\ClusterStorage\volume1\hyper-v\oktest-lb1\oktest-lb1.vhdx. db2 uses O_DIRECT flag (uncached i/o) for its database ...
1
vote
0answers
44 views

How to track down bad performance on an api-server

If my api-server shows bad performance, such as high cpu - can this be blamed on the service or on the server? If a regular app-server shows bad performance, all I can do is track down the methods ...
1
vote
0answers
96 views

IIS hanging when running Active Reports, possibly splwow64.exe

We have a Windows 2008 R2 web server running our web app on IIS and when running a particular page which generates a PDF (using Active Reports https://activereports.grapecity.com/) it takes between 1 ...
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vote
0answers
16 views

What is involved in adding ZFS cache stats to orca?

I am interested in looking to add ZFS cache stats into existing orca performance monitoring that we have. Particularly, I am interested in the output of echo ::memstat | mdb -k Am still in the early ...
1
vote
0answers
108 views

Why a VPN slows down LAN access?

We have an access server providing VPN to some of our clients and the workforce with laptops. They usually connect from outside of the office, and everything works fine. However, for simplicity and ...
1
vote
0answers
127 views

Windows Server 2012 Disk Operations Freezing

I've got 2x brand new Windows server 2012 R2 servers. Fresh install. All Windows updates applied. One on a brand-new physical server, and the other in our VMWare cluster. When I try and perform a ...
1
vote
0answers
52 views

File IO being slow

I've rented this root server with a RAID1 mdadm software raid setup. Using dd to benchmark the file IO speed it achieves 230MB/s write (default blocksize). Certain tasks such as mysql are way slower, ...
1
vote
0answers
342 views

How do I interpret a very high Avg. Disk sec/Write perfmon value?

Short version: Is the perfmon screenshot shown below enough evidence to say "something is wrong with your storage system"? Long version: I am debugging a performance problem: Some SQL Server query ...