11-26-2014 11:41 PM - edited 03-05-2019 12:14 AM
Hello,
My Database Applications run very very very slow when traversing a L3 MPLS (10mbps).
The network latency is about 29ms and regular windows copies are fast, but it takes a while to run any application from the remote server.
What could cause the so big delay to run apps?
Thank you,
Sergey
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11-27-2014 03:31 AM
You database applications are running slow compared to?
I.e. have you run them across any other WAN offering about 29ms latency?
11-28-2014 05:09 AM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
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Posting
Yes, your WAN slowness might be mostly due to WAN latency.
Often network applications are written very interactively and the additional latency, on WAN, can slow them greatly compared to LAN, where latency is often sub millisecond.
Your "regular windows copies are fast" likely because bulk data transfers have "windowing" which allows them to sometimes (eventually) copy as fast as they will on a LAN. (If the Windows file copy, though, shows current transfer rate, you might notice the initially transfer rate takes a longer to get to full speed on the WAN vs. a LAN. If you do, that's also because of WAN latency.)
Your latest post also mention IPSec and SSL VPN. These too can slow things down a bit. One notable potential issue is packet fragmentation for encrypted packets; this may, or may not, be happening on your database application. Fragmentation generally only happens on nearly full sized packets.
11-26-2014 11:51 PM
проверь реальную скорость канала с помошью iperf с клиентского копьютера до сервера
также проверь мту и пропиши на интерфейсах реальный мту если отличается от 1500
если нет проблеи ни со скоростью передачи данных ни с мту тогда значит проблема в самой базе. там плохой дизайн таблиц плохой дизайн индексов или самого приложения.
у нас однажды разработчики в кавычках сделали програму которая копировала все таблицы с сервера на клиентский компьютер вместо того чтобы послать sql запрос на сервер базы данных
11-27-2014 03:31 AM
You database applications are running slow compared to?
I.e. have you run them across any other WAN offering about 29ms latency?
11-27-2014 09:49 PM
The Database App is running much slow via MPLS than running locally via LAN.
Also It running slow via IPSEC and SSL VPN, so I think it make sense to say that Database App running slow via WAN link. At the same time it works great via 10Mbs LAN.
11-28-2014 05:09 AM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
Yes, your WAN slowness might be mostly due to WAN latency.
Often network applications are written very interactively and the additional latency, on WAN, can slow them greatly compared to LAN, where latency is often sub millisecond.
Your "regular windows copies are fast" likely because bulk data transfers have "windowing" which allows them to sometimes (eventually) copy as fast as they will on a LAN. (If the Windows file copy, though, shows current transfer rate, you might notice the initially transfer rate takes a longer to get to full speed on the WAN vs. a LAN. If you do, that's also because of WAN latency.)
Your latest post also mention IPSec and SSL VPN. These too can slow things down a bit. One notable potential issue is packet fragmentation for encrypted packets; this may, or may not, be happening on your database application. Fragmentation generally only happens on nearly full sized packets.
11-28-2014 10:06 AM
OK, good to know.
Do you think increasing of speed on WAN can help or there are will not be any difference for applications due to the same value of latency???
Also I noticed that DB apps are using SMB2 protocol for communication.
I am going to try SMB3 on Windows 8.
11-28-2014 06:37 PM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
If the problem is latency, increasing WAN bandwidth, unless there's congestion, will likely not help.
In Vista, and later, Windows version, Microsoft has made improvement to TCP and/or SMB, but again, they don't help a lot with distance based latency for interactive traffic.
11-29-2014 12:42 PM
OK, that make sense. Thank you for your help.
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