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

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24 views

How to optimize Apache speed for serving static content?

I'm well aware ngix is much better for static content, but I can't use it. Otherwise I have full access to my server (VPS). I've found numerous articles and posts about optimizing apache, but it's ...
1
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1answer
39 views

Benchmarks for server response time [on hold]

I was testing my website’s performance on Google Page Speed and it mentioned the response time at It average between .6-.8 seconds. What’s the optimal server response time that’s acceptable? Is ...
0
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0answers
8 views

Something like Receive Segment Coalescing for UDP

The TechNet page on RSC states: RSC is defined only for TCP connections. RSC does not work with User Datagram Protocol (UDP) and other transport layer protocols. This is of course ...
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0answers
23 views

How would a server referenced in HBOs Silicon Valley work? Uses GPUs to run a compression algorithm. [on hold]

I was watching the HBO show Silicon Valley and they were setting up a a server using GPUs. Now I know a GPU is better than a standard CPU for mathematical calculations, but I'm curious how this would ...
3
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0answers
38 views

Intel RS3UC080(LSI3008) + Samsung Evo 840 = slow writing performance? [migrated]

I am getting pretty slow writing performance in comparison with my Z87 board. Does anybody know if these results are to be expected out of the Intel RS3UC080 or what the problem might be if there is ...
7
votes
1answer
102 views

Is it possible to process millions of datagrams per second with Windows, using a vendor agnostic API?

I am investigating if I can implement an HPC app in Windows that receives small UDP multicast datagrams (mostly 100-400 Bytes) at a high rate, using a dozen or up to maybe 200 multicast groups (i.e. ...
6
votes
2answers
180 views

does adding heaps of drives to a raid 0 increase performance?

does adding heaps of drives to a raid 0 increase performance? i know that two drives in a striped raid will usually be faster than a single drive but will i notice a difference in performance between ...
6
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0answers
42 views

Why higher await time for DM multipath device than underlying device?

We have a CentOS 6.4 based server attached to Hitachi HNAS 3080 storage and observed the kernel remount the filesystem in read-only mode: May 16 07:31:03 GNS3-SRV-CMP-001 kernel: [1259725.675814] ...
1
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1answer
25 views

Application Performance & Interrupt Affinity

Quoting the RedHat Performance Tuning Guide 3.3.7. Setting interrupt affinity Interrupt requests have an associated affinity property, smp_affinity, that defines the processors that will ...
2
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1answer
30 views

Is there a maximum 'anything' when running a high number of processes on Windows

I have a series of well optimised services written in house using .Net running on many 512GB RAM server (a mix of Xeons including E5-2697 V2 etc). Is there a maximum handle, process, thread count that ...
2
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1answer
31 views

Does SAS server rotate always in it's default speed (like 10K, 15K)

I have some concerns about disk throughput in order to plan my SQL Server deployment. I know from experience that consumer SATA disks sometimes go into sleep mode when not used for a longer period. Do ...
0
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0answers
60 views

Slow hard disk speeds on Windows Server 2008 [closed]

I have already looked at many articles regarding slow read/write speeds on Windows Server, however they either involve Server 2008 R2, 2012, or are related to speeds over the network. I have 5 ...
14
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1answer
196 views

Vendor whitepaper says: 5Mpps no prob. I'm already hitting a wall at 120kpps. Where's the bottleneck?

HP's whitepaper on their QLogic (fka Broadcom) NetXtreme II adapters, which includes the specific NIC that I'm testing, states (page 7) that their small packet performance for packets up to 256 ...
2
votes
1answer
28 views

How much of a performance does using QEMU virtualization incur on Windows?

How much of a performance does using QEMU virtualization incur on a Windows host, when both the host and vm are running the same CPU? Older articles indicate that using kqemu avoided the slow down in ...
5
votes
2answers
185 views

raid controller data transfer rate

I'm going to buy an 8-port raid controller for which the declared data trasfer rate is "Up to 6Gb/s per port". The declared connectors are "Two mini-SAS SFF8088". The maximum number of supported ...
1
vote
0answers
21 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 ...
2
votes
1answer
47 views

SAN performance too low?

I've noticed my new EMC VNX5200 SAN tends to perform better after "burning in" a partition. By this I mean filling the partition with different junk data and deleting everything a few times. Asked my ...
7
votes
2answers
160 views

Extreme UDP packet loss at 300Mbit (14%), but TCP > 800Mbit w/o retransmits

I have a linux box I use as the iperf3 client, testing 2 identically equipped Windows 2012 R2 server boxes with Broadcom BCM5721, 1Gb adapters (2 ports, but only 1 used for the test). All machines are ...
2
votes
1answer
56 views

Are RAID 5 systems suitable for larger disk sizes?

Why is it generally considered that RAID 5 systems are not suitable for larger disk sizes? Is the same true for RAID 6?
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2answers
45 views

Why sometimes AWS EC2 works really slow?

I do only one thing one this server - encoding videos by ffmpeg. And sometimes it does work ok, sometimes it's really slow. I run the same command just for a test: $ sudo time ffmpeg -i test.mp4 ...
1
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0answers
38 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, ...
12
votes
4answers
243 views

tcpdump increases udp performance

I'm running a set of load tests to determine the performance of the following setup: Node.js test suite (client) --> StatsD (server) --> Graphite (server) In short, the node.js test suite ...
2
votes
2answers
47 views

Postfix long dns queries

I use my postfix server as a relay to another provider. I dig a little to find out why sending a simple mail takes so much time. I figure out that postfix do complete DNS queries for each single mail ...
-3
votes
1answer
117 views

Mysql showing 100% CPU usage [closed]

I'm experiencing some problems with my MYSQL server installed with Cpanel. My server is showing 100% usage of mysql even if I don't have too much traffic on web. I am running CentOS 6.5x64 with 80GB ...
0
votes
1answer
31 views

Ubuntu Trusty: virt-manager performance over WAN… 40+ secs freezes

I'm using the virt-manager GUI 0.9.5-1ubuntu3 on my laptop running Ubuntu 14.04 against a server located some distance away (same OS) and getting rather unpleasant performance. Laptop-server pings ...
0
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2answers
33 views

Same number of clients - multiple WAPs vs Single WAP

We purchased a device that acts as a WAP through which you can connect a mobile device and share its content onto a projector or tv. My question is - if we have multiple deployments of this device, ...
1
vote
1answer
25 views

server connection speeds can the be judged by a online speed test [closed]

Im currently investigating some issues on my windows servers. Ive run a test from my hosting provider and I think its incredibly slow. I've also run the same test but from my amazon AWS box and ...
3
votes
4answers
199 views

What is a core, and will purchasing more cores for my VPS speed up page load times?

I recently purchased a premium WordPres plugin called Hide my WP. I planned on using this plugin for my nonprofit organization's website, which is a multisite WordPress installation with an SSL. ...
1
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0answers
34 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 ...
18
votes
4answers
1k views

Software vs hardware RAID performance and cache usage

I've been reading a lot on RAID controllers/setups and one thing that comes up a lot is how hardware controllers without cache offer the same performance as software RAID. Is this really the case? I ...
0
votes
2answers
25 views

MyISAM Throughput spike at 12000 record insert

I am testing database performance with bulk record inserts. Both systems are identical apart from storage engine **Database 1000 4000 12000** MySQL_InnoDB 60.95330976 ...
4
votes
2answers
232 views

Samsung 850 EVO + HP P410 limited iops?

I´m experiencing a weird write iops limitation with a HP P410 256mb cache controller and 4x consumer grade ssd´s (Samsung EVO 850) in RAID5/10. After upgrade to latest firmware (6.64) for HP P410 ...
7
votes
1answer
130 views

What do users see when Apache reaches MaxClients?

Occasionally, in my Apache error log, I will find: [error] server reached MaxClients setting, consider raising the MaxClients setting I've purposely lowered MaxClients in the past (to 60) due to ...
0
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1answer
34 views

Does Apache mod_status give any insight to tuning Apache config?

Does the Apache mod_status output give any insight to tuning Apache prefork config? For example, using Apache's mod_status, I figured out that My server gets 3 requests/sec average, the range is ...
1
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0answers
24 views

Run application from network drive takes long

This problem started recently, and I wasn't able to find a solution. Not even formatting solved. We have a program on our network drive and the Whole company accesses to this single exe. Usually the ...
14
votes
2answers
290 views

NFS poor write performance

I have two machines connected with 10Gbit Ethernet. Let one of them be NFS server and another will be NFs client. Testing network speed over TCP with iperf shows ~9.8 Gbit/s throughput in both ...
0
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0answers
15 views

How do vCores work in Virtuozzo Virtualization?

We are evaluating vServers based on Virtuozzo. The marketing says 2 dedicated Cores 6 virtual Cores /proc/cpuinfo lists two cores. The support told us, that the virtual cores will be used when ...
0
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0answers
37 views

CPU usage of server extremely low and webpage load time high?

On a weekday at a time where very few use the optimized website on the server, the time for the page to completely load excluding 3rd party advertisements is about 0.6 seconds to 1 second. Now when a ...
2
votes
1answer
23 views

Same hardware/software, significant difference in performance

Introduction I have two sets of machines, set A and set B, with apparently the same hardware/software configuration, but with a significant difference in performance. Machines in set B are up to x4 ...
0
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2answers
51 views

How to speed up (very remote) overloaded server connection

I'm living in France and I need to load a page from a far far away server (still in the same galaxy). "Far" is Canada to me, meaning over 8 000km of internet cable. The problem is, this server is ...
0
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0answers
45 views

My website takes a long time to START loading

My website takes a long time to start loading. Once it starts there's a 3 second load time which is fine, but it seems to do nothing for 7 seconds first. Can anyone help me to understand what those ...
1
vote
1answer
21 views

SAS direct dual link connection to an embedded LSI Fusion-MPT controller

This is a hardware question. I have a dual-link SAS hard drive and a Intel S5000XVNSAS motherboard without the drive cage option. Recently, I bought a direct dual-link cable in amazon. But when ...
0
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0answers
115 views

PerfMon: Processor Queue Length - Random high spikes

I'm investigating alleged high CPU usage on one of our client's servers. After about 1 business day of "normal" activity, PerfMon is reporting the following values for Processor Queue Length, and I'm ...
0
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2answers
198 views

RAID1 very slow with LSI card and 2x Samsung EVO 850 drives

not sure if I'm checking it correctly, but here is what I have. Desktop, LSI 9260-8i card, see config below. 2x 500Gb Samsung 850 EVO drives. I also have Samsung 830 drive attached to motherboard ...
0
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0answers
61 views

Server high memory and cpu - no leads

I've been asked to troubleshoot a server hosting our application at a client's facility. The client has complained to us on two separate occasions in the last week - week and a half. In one instance ...
0
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0answers
12 views

Postgres 9.3 maximal cluster size with streaming replication [duplicate]

First, I quote from https://wiki.postgresql.org/wiki/Binary_Replication_Tutorial: In Streaming Replication, the master and the standby have special processes called the walsender and walreceiver ...
-1
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1answer
26 views

Measure traffic of streaming audio/video in whole office

I would like to measure the different traffic used in our office, specifically streaming of audio and video. I'm trying to assess whether there is any affect of people using streaming on our internet ...
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votes
1answer
25 views

Synchronize Staging Server and Live Server [closed]

We have staging and live server at our office. Where Live code and DB changes are far more advanced than staging one.This application developed under php and DB is mysql. Earlier we used to work in ...
-4
votes
1answer
43 views

mysql hot add memory

Is it possible for currently running jobs in MySQL to utilize memory that's been hot added? It looks like when memory is hot added to the VM the currently running jobs are not utilizing the additional ...
4
votes
2answers
174 views

How to interpret values of Perfmon counter Hyper-V Hypervisor Virtual processor\CPU Wait time per dispatch

So there is a lot of guidance on the web that advises tracking the values of the Perfmon counter Hyper-V Hypervisor Virtual processor\CPU Wait time per dispatch as the nearest Hyper-V equivalent of ...