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Questions tagged [cache]

A location or process for storing of transitory or temporary data in order to improve application or system performance.

1588 questions
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What is the latency WITHIN a data center? I ask this assuming there are orders of magnitude of difference

I am trying to figure out something that I just cannot find a good answer to. If I have say a REDIS cache (or some external in-memory cache) sitting in a data center, and an application server sitting in the same data center, what will be the speed…
Neeraj Murarka
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When to use or not to use sendfile on/off in Nginx?

We have this setting in our nginx.conf for quite a while. sendfile on; When we have updated a file e.g. /js/main.js and access from browser https://test.com/js/main.js?newrandomtimestamp, it will still load the older version unless we do a full…
forestclown
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Does a RAID controller with an NV cache improve the performance or integrity of an SSD array?

I am planning to purchase a server (Dell PowerEdge R740) with SSDs in RAID 10, and my priorities are write performance and data integrity. It will be running Linux. The SSDs have write caches with power loss protection. It seems like these are my…
sourcenouveau
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Is there a way to get Cache Hit/Miss ratios for block devices in Linux?

Is it possible to see in Linux how many read and write requests from user space end up causing cache hits and misses for block devices?
Kyle Brandt
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Nginx not caching data

I have a REST API behind an nginx proxy. Proxying works fine, however I am unable to cache any responses. Any help would be much appreciated: Nginx config: worker_processes 10; error_log logs/error.log; error_log logs/error.log notice; error_log…
nick_v1
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How can I clear the "authentication cache" in Windows 7 to a password protected samba share?

I have a Linux samba server and have explicitly listed users that can access the folder. I have successfully congfigured Samba to require a username and password when accessing the share from windows (using the smbpasswd, etc.). But now I want to…
Chris Drumgoole
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deleting linux cached ram

I have a webserver that has 8GB of ram and is running a pretty intensive php site (1 site) that does file manipulation, graphing, emailing, forums, you name it. The environment is far from static which leads me to believe that very little could be…
Patrick R
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Main differences between SSI (Server Side Include) and ESI (Edge Side include)

I need to include dynamic content into static pages at web server level. The 2 options I have found so far are Server Side Include (SSI) and Edge Side Include (ESI). While the origins of SSI seem old and obscure (that cached page from 95 from…
Max
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SATA Disks that handle write caching properly?

It's pretty common to see advice to disable the write cache on individual disks used for databases because otherwise some disks will acknowledge writes that haven't yet made it to the disk surface. This implies that some disks don't acknowledge…
eas
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2 answers

Nginx caching symlinks

I have a deployment system on my web server, every time an app is deployed it creates a new timestamped directory and symlinks "current" to the new directory. This all workded good and great on apache, but on the new nginx server I've set up, it…
Auris
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Hardware RAID controller cache battery failure frequency/lifetime?

I'm in an environment that contains many Supermicro servers equipped with Adaptec and LSI MegaRAID hardware RAID controllers. These controllers contain battery-backed cache modules to help boost write performance and protect data in-transit. A…
ewwhite
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7 answers

SQL Server - Force DB in memory?

We have a beefy Windows 2008 x64 server (4 x 4 core CPU, 32GB RAM) running SQL Server 2005 64-bit. We have a small (6GB) but very important database that is somewhat slow to access until the pages are cached in memory (the usage is very much random…
Matt Rogish
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Does my ISP cache the DNS?

I went to my zoneedit.com, changed mydomain.com to point to a different IP. But changes haven't taken affect yet. Is this because my ISP DNS is caching?
Alex
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Linux; What is stripe_cache_size and what does it do?

I am currently building a software RAID under Linux using mdadm utility and I've read a few articles that describe how to increase the stripe_cache_size value for that RAID and how to calculate an appropriate value for stripe_cache_size. I have…
jwbensley
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Managing battery relearn cycles on LSI and similar RAID controllers

How do engineers deal with RAID controller battery "relearn" cycles? As noted in: What's a "battery relearn" on a LSI MegaRaid?, relearn cycle discharges the RAID controller battery (BBWC or BBU), thus removing the write cache acceleration. The…
ewwhite
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