Questions tagged [cache]
A location or process for storing of transitory or temporary data in order to improve application or system performance.
1,600
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Cache request in async way
There's plenty of options to cache requests on web servers/proxys, but i'm looking for a way to made incoming requests to "wait" until the cache is ready and then response with the cache to ...
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Can Varnish automatically determine which storage medium should be used to cache an object?
For instance, I have an incredibly slow and archaic backend provider with requests regularly taking in the tens of seconds. We also have a machine with moderate memory and large storage. Ideally, I'...
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935
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HTTPS session resumption sometimes partially working
I'm having an issue with ssl session caching. To test if server configuration is OK, I use the following command:
echo | openssl s_client -connect <server.com>:443 -reconnect 2>/dev/null| ...
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311
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How do I manage last level cache among virtual machines?
Let's say I am gonna run a server to lend virtual machines to clients, like other CSP vendors do. My server has 20 cores, so there will be a total of 5 instances with 4 cores.
What I am worried about ...
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Sending cache headers only for a single request [or for a request following a certain path string]
I have the proxy pass in nginx config defined as follows:
location / {
proxy_pass http://localhost:3001;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $...
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2
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On AWS, is it possible to have CloudFront proxy requests to API Gateway while maintaining the request's query string?
I have a CloudFront distribution configured with multiple Origins, including an API Gateway deployment.
I'm trying to create a Behavior on CloudFront so that any requests received to a /api/* path ...
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2
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736
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Is it better to have a centralized [redis] caching instance or per instance?
I have a VPC in AWS that contains a public and private subnet. In the private subnet, I have two load balanced EC2 app servers, and an EC2 Database/Cache server.
The two app servers connect to the ...
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2
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1k
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Cache response with nginx and browser, but not CloudFlare
My backend application sends Cache-Control headers so that NGINX and the browser can cache responses.
I would like CloudFlare to not cache these responses. This is because they may have non-public ...
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1k
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Alternative to using if statement in nginx location block
Nginx config goal:
Check if a certain cookie exists (doesn't matter what the value is)
If it doesn't exist, include a particular config import.
I only want to apply my rules to certain Locations, I ...
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1
answer
3k
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Using an Nginx proxy cache to prevent duplicate requests?
I am using an Nginx proxy as a front-end to a web application that tends to get identical duplicate requests milliseconds apart, causing duplicate items in my database.
I thought I might be able to ...
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Slab UnReclaimable Using 14GB
I need help to understand what is this slab unreclaimable memory usage, I know that is related to cache.
Here is the output of /proc/meminfo
cat /proc/meminfo
MemTotal: 23373884 kB
MemFree: ...
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2k
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Varnish crashes on bigger files
Overall, I serve very small files. Think about images and small videos. Caching these with Varnish is like a breeze and doesn't give me any issues.
The problem I am having, is when I am downloading a ...
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2k
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Best practice in Redis is to rename the command 'FLUSHDB'. But now I get an error with Laravel when I want to clear the cache
In Laravel, you can set the cache to Redis. However, when I clear the cache with php artisan cache:clear, I get the error: ERR unknown command 'FLUSHDB'
I know what the problem is because I have ...
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1
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10k
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My browser keeps showing cached page despite sending no-cache, no-store, must-revalidate from server in response header
The content on our pages keep changing and hence we do not want the browser to cache the page or show cached page or our users. But the browser keeps showing cached page despite sending no-cache, no-...
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What is .max_connections parameter in varnish vcl and how to caculate this value for backend nginx server
I have seen .max_connections parameter in varnish default.vcl and by seraching in web, found the artile below
.max_connections: how many connections you authorize Varnish to open to this backend. ...
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460
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Forwarding request when serving from NGINX cache - Is this possible?
I have enabled caching with Nginx. I followed the official docs and it works fine. What happens is, when the request comes in for the first time, it is proxy passed to a server. The response is cached....
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Why does Firefox still make connections to server although the HTTP resources are shown as "cached"?
I am confused by the way Firefox shows loaded resources as cached but then I can see the browser issues new DNS query for the domain name and contact the HTTP server again.
Below is a simple example ...
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Client-side caching when using CSP with nonces in nginx - how do you use weak caching validators/etags?
I'm using nginx's expires directive; its etag directive as well as the Last-Modified header (if I understand correctly) are on by default.
In order to allow specific inline JavaScripts when using ...
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0
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54
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Apache2 eating all the system RAM
I'm serving on Images ( JPG|JPEG|PNG ) from an apache server. after sometime, the system cache becomes sooo populated that no other programs are able to run -- like recently I noticed that one of the ...
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0
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2k
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How to disable RDP bitmap caching system wide
I'm trying to find a way to completely disable bitmap caching for RDP clients (In Windows 10 the setting is called "Persistent bitmap caching") on a Windows system, either through GPO or ...
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1
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754
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Nginx cache - pass through cache-control: max-age but cache for longer
I have an origin server behind a nginx proxy in a container, with a CDN in front.
I want my HTML pages to cache on the CDN for 1 minute, so I set the cache-control: public and cache-control: max-age=...
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1
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2k
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zfs remove wrongly added device
I accidentally added a device as normal pool device instead of cache device. Is there a way undo this? (I basically forgot to type cache when adding the device)
I can't remove it
root@dmi-vault2:~# ...
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277
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nginx caches the same file with versions
I added default setup for cache on Nginx. On usual refresh I receive 304 but in the cache folder there are additional files with versions like 02a9299b4f7a308b588544c1a735cc1e.0000000002, ...
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549
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Can nginx proxy_cache replace fastcgi_cache?
If nginx is already used with proxy_cache, is there still any need to use fastcgi_cache?
In other words.. When using nginx proxy_cache, there is no more need for fastcgi_cache?
3
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1
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6k
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NGINX - Caching not working - Always MISS
I'm currently working on enabling caching on a NGINX (Reverse Proxy).
With this configuration, the value of X-Proxy-Cache is always MISS.
My current conf (in /etc/nginx/conf.d) :
proxy_cache_path /...
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1
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95
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Cache Control Mechanisms
I m trying to find the difference between a server configured with “cache-control max-age=0, must revalidate” and server with “cache-control: no-cache, no-store”.
So for the first, to my understanding,...
2
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1
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154
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Could Cloudflare slow down writing process to database?
I have two identical WordPress sites - live and staging - both sitting in the same EC2 server. The live is using Cloudflare, the staging is not. I noticed that database writing processes are slower in ...
1
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0
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30
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cache_writeback of thin-provisioning-tools running failed
I use Ubuntu 16.04 with kernel 5.4 and thin-provisioning-tools version 0.8.5
I want to test the cache_xml and cache_writeback tools of thin-provisioning, but it failed.
It always failed and I don't ...
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2
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How to optimize memory with Fail2Ban, Journal and Clamav
I use VestaCP on Debian 9.
Yesterday I received 3 email alerts related to cron. All three contain the same error message: /bin/sh: execle: Cannot allocate memory.
So, I started with the free --mega ...
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465
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How to reduce "RAM Cache + Buffer" size due to scrapy
I am running a couple of spiders in parallel by scrapyd 1.2. Each process will raise the Buffer during the crawl significantly as seen in the chart. What is this value and how can I reduce the ...
2
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1
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9k
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Can squid cache for https requests?
Just as said in "Can squid cache objects from HTTPS sites?", to cache objects from https sites, one would need to use the SSL bump feature.
But, I can set https proxy as well as http one, even the ...
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2
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972
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Are images cached or not?
I'm a bit perplexed on debugging of caching circumstances in the landscape of Apache (webserver) and Nginx (reverse proxy):
I'm trying to get into knowledge, whether images are properly cached or not....
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1
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721
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Why would Apache log different response sizes for the same url?
I noticed a couple (ostensibly-)harmless log entries, and--I'm admittedly overthinking this by a mile--got curious about Apache2 response sizes.
This Ukranian crawler † hit my web daemon, two seconds ...
14
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5
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40k
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How to clear (remove/delete) certificate (ssl/https) cache from chrome browser?
I lost many hours while setting up some self-signed certificates; the problem turned out to be that the browser (Chrome) cached a bad version of the certificate and then just wouldn't let go. I did ...
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0
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154
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Purge cached data from Apache mod_cache
How to force purge cached response from Apache mod_cache (mod_cache_disk)?
https://httpd.apache.org/docs/2.4/mod/mod_cache.html
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391
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My varnish devicedetect.vcl is not working site no longer responsive
default.vcl
# Default backend definition. Set this to point to your content server.
backend default {
.host = "127.0.0.1";
.port = "8080";
}
sub vcl_recv {
# ...
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1
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1k
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How to remove the least-recently-used image layers from Docker cache?
I would like to (1) avoid running out of disk space due to Docker filling up its cache and (2) easily recover from such situation without discarding the cached objects that have been used recently. ...
0
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0
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203
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How to move nginx cache contents to another machine
I'm running a nginx server on debian 9 to save some bandwidth for my s3 bucket. It currently holds 300gb of data. In order to save some money I want to move this data to another server. I'm currently ...
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2
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1k
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Can you cache the 'find' command?
I wrote a simple shell script which uses the 'find' command so non-technical users can do a search on the file server through a web browser on the LAN. It works, but sometimes it has a long execution ...
2
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1
answer
3k
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Is it safe to use proxy_ignore_headers Vary?
I use a Nginx server that acts like a cache/reverse proxy for my Apache origin server.
I was strugling to debug high rate of cache MISS when I found that it is because the response header Vary: ...
1
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2
answers
1k
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Prevent Cloud CDN from serving cached elements?
I have some problem with Cloud CDN.
I've added a CDN to a bucket connected on an instance.
I need to get an element from CDN, but this element is updated each 1 sec from my server.
What happen is ...
6
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1
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1k
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Microsoft Storage Spaces Write-Back Cache exists on HDD-only single-tier parity disk?
I created a parity storage space on 3x external USB 4tb HDD attached to a Windows 10 1809 machine. I then moved those HDDs to a Server 2019 1809 machine and added 1x additional 4tb HDD.
I noticed ...
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1
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4k
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Alter Nginx reverse proxy cache header from Public to Private
I have an Nginx cache server getting content from an origin server, the origin server sets Cache-Control to Public so my Nginx cache server can cache the content and make less requests to origin. But ...
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1
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2k
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NGINX cache (same URL) first returns MISS to all Chrome, Curl and Wget
I have a nginx cache proxy that gets content from an apache origin server.
I make requests from curl, wget and Chrome to verify the cache response. Problem is that, for same URL, I always get a MISS ...
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0
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32
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Seprated location block for same URI by different query-string Nginx
These are my URIs
/posts.php?action=get_single_posts
/posts.php?action=search
/posts.php?action=get_all_posts
I need 2 separated location block for these URIs in Nginx because I want to cache ...
1
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1
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1k
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set correct request host to avoid this infinite loop in nginx
I configured this nginx server for example.com and www.example.com to be a cache/reverse proxy, taking data from mysource.example.com
It seems to work ok in browser, but I noticed significant google ...
0
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1
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680
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Memcached not working in PHP file but working on SSH - CentOS
On my CentOS 7, Memcached is running and working on SSH but not working in the PHP file. I've followed this article: https://www.mynotepaper.com/install-memcached-on-centos-7. This method was working ...
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1
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2k
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nginx mixing cached content between my different domains
I don't know if this is a bug or I am defining cache incorrectly, I have a nginx cache (reverse proxy) server that is used by 2 different domains (mydomain1.com and mydomain2.com), different content, ...
2
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2
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3k
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Laravel View Cache location
Sorry if this seems trivial, but I need to be sure:
Where does Laravel 6 store the view cache? On the cache server or in the storage folder?
Does it get stored in my redis if I set it as the cache ...
5
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1
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3k
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Why is the ssl session cache ( ssl_session_cache) disabled by default in nginx?
In nginx, the ssl_session_cache directive has a default of 'none'. ref
However, in the documentation for configuring HTTPS server, it's advised to turn on the ssl session cache, as it explains that ...