Questions tagged [scaling]

138 questions
101
votes
8 answers

What limits the maximum number of connections on a Linux server?

What kernel parameter or other settings control the maximum number of TCP sockets that can be open on a Linux server? What are the tradeoffs of allowing more connections? I noticed while load testing an Apache server with ab that it's pretty easy to…
Ben Williams
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47
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5 answers

How many requests should my webserver be able to handle?

Not going into specifics on the specs since I know there is no real answer for this. But I've been doing load testing today with the ab command in apache. And got to the number of 70 requests per second (1000 requests with 100 concurrent users), on…
Ólafur Waage
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21
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2 answers

How can I make Microsoft Management Console high-DPI aware in Windows 8.1?

Since Windows 8.1 doesn't allow system-wide "Windows XP style" high DPI support, how can I make the Microsoft Management Console apps (mmc.exe) high-DPI aware? There is no "Troubleshoot compatibility" context menu item for it.
user20939
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20
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4 answers

Which database server scales better: PostgreSQL or MySQL?

I'm working on a website that could eventually have a very large database. The website will be an art community not until deviantART. I'll be running a lot of queries for analyzing how the site is used. I expect some of the queries to kill the…
epochwolf
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19
votes
4 answers

How to allow elastic load balancer through port 80 in security groups?

I want to temporarily block port 80 for the outside world, but want the load balancer to pass through the firewall (via security group) so it won't see the instance as unhealthy. How can I do that? Update: I also want to know how can I allow only…
Liron Harel
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17
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3 answers

Is there a way to add more backend server to haproxy without restarting haproxy?

We want to be able to add more backend servers on demand. Right now I don't see a way to add more backend servers to the config file without restarting haproxy.
Jan Deinhard
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16
votes
2 answers

Tips for maximizing Nginx requests/sec?

I'm building an analytics package, and project requirements state that I need to support 1 billion hits per day. Yep, "billion". In other words, no less than 12,000 hits per second sustained, and preferably some room to burst. I know I'll need…
linkedlinked
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13
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5 answers

How do services with large ingest rates install enough hard disks fast enough?

Amazon, Facebook and Google must take in TBs if not PBs per day, so does that mean they have people continuously installing new hard disks and cables in new racks in the same way you might build a regular server, or is there a different technology…
jl6
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11
votes
5 answers

AWS: Multi-region setup using single RDS instance

I'm trying to scale our web application (PHP, MySQL, memcache) in a multi-region scheme. Currently we are using a setup with two EC2 instances behind an ELB and an RDS instance, all of them in US-EAST (Virginia) region. We would like to have a…
Ion
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10
votes
6 answers

How to identify heavy write to disk?

I have this problem with server running CakePHP application. The server is insanely slow, I first thought that it's application problem, but then I found constant 5-6MB/s write to disk. What is the easiest way to find cause of such a heavy…
Jakub Arnold
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10
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1 answer

Recommendations for Elastic Search hardware

Are there any good guides for hardware level to support ElasticSearch? Are recommendations for Lucene or Solr a good place to start? We're looking at rolling out a deployment starting with 27 million documents, 8TB of data add 300k documents per…
James Socol
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9
votes
2 answers

Large VPN network (~600 servers) with OpenVPN

I'm doing a preliminary study for a contract to build a VPN network between ~600 remote servers running Linux CentOS 6 (+ their 600 private LANs). The network is supposed to be star-based, so that each remote server connects to a central server(s)…
Giovanni Bajo
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9
votes
3 answers

The best way to share a file uploads directory across horizontally scaling web servers

I'm currently trying to spec up a horizontally scalable cluster for a drupal based web app, that looks something like the colorful diagram below: The load balancer implements sticky sessions, so a user keeps state once they've been allocated a…
Chris Adams
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9
votes
8 answers

More RAM vs. more servers

I was recently asked "Do you know when to decide between going for more RAM or more servers?" (in the context of scaling data mining applications). I had no idea, so what are some ways to decide? I have very little knowledge of architecture and…
user357972
8
votes
10 answers

Where to purchase a server capable of 512GB of RAM?

Where can I purchase a single server capable of 512 GB, yes GB, of RAM? The most I've seen is 256 GB (32 DIMM x 8 GB per stick)
Timk
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