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Questions tagged [gzip]

Gzip is any of several software applications used for file compression and decompression. The term usually refers to the GNU Project's implementation, "gzip" standing for GNU zip. It is based on the DEFLATE algorithm, which is a combination of Lempel-Ziv (LZ77) and Huffman coding.

Gzip is any of several software applications used for file compression and decompression. The term usually refers to the GNU Project's implementation, "gzip" standing for GNU zip. It is based on the DEFLATE algorithm, which is a combination of Lempel-Ziv (LZ77) and Huffman coding.

Gzip is based on the DEFLATE algorithm, which is a combination of LZ77 and Huffman coding. DEFLATE was intended as a replacement for LZW and other patent-encumbered data compression algorithms, which, at the time, limited the usability of compress and other popular archivers.

"Gzip" is often also used to refer to the gzip file format, which is:

  • a 10-byte header, containing a magic number, a version number and a time stamp
  • optional extra headers, such as the original file name
  • a body, containing a DEFLATE-compressed payload
  • an 8-byte footer, containing a CRC-32 checksum and the length of the original uncompressed data

source: wikipedia

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is gunzip atomic?

I have two scripts that watch a directory (postgres warm-standby) one script copies compressed files into the directory and then uncompresses them. the other script watches for the uncompressed files and then ingests them into postgres. Im…
Arthur Ulfeldt
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Backup MySQL database and gzip

I'm trying to get a little more usefulness out of my MySQL backups. I'm wanting to gzip my backup when it's completed from a cron job. Here's the script I have so far to do the backup. #!/bin/sh date=`date -Iminutes` mysqldump --all-databases >…
Tim Meers
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Gzip pre-compression

I'm using mod_deflate to compress my .css and .js files on the fly: AddOutputFilterByType DEFLATE text/text text/html text/plain text/xml text/css application/x-javascript application/javascript The problem is…
user57192
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IIS7 is gzipping files but not serving the gzipped version

By following a number of helpful blog posts I have configured IIS to gzip my static files. I have even enabled Failed Request Tracing and filtered to the 200 status code, and I can see the successful compression events taking place as well as the…
ptrin
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Use mod_deflate or gzip for centos5+apache

I'd like to compress the JS and CSS (perhaps also html?) files that I'm sending out. I've read a lot about gzip and mod_deflate but I'm not really sure what's the best to use? I'm looking for the easiest thing to maintain and to reduce bandwidth on…
solsol
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"tar czf" versus "tar cf - | gzip": are they different? (or how to improve a backup)

I want to speed up my backup done with tar czf, the common way to do it. But day by day my backed up files grow so it becomes slower. I was thinking to take advantage of the several cores available in my server and I was wondering if there is any…
Dario Castañé
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Apache GZIP for images - any reason?

JPEG, GIF, PNG and WEBP images are already compressed. Is there any reason to serve them up using GZIP compression, regardless of whether or not the client says it may accept GZIP compression? curl -H "Accept-Encoding: gzip" -I ^ …
Lumi
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Pagespeed delivers content with gzip header but not gzip content all out of nowhere?

All out of nowhere our website did not longer load CSS. The Chrome browser console showed Error 330 (net::ERR_CONTENT_DECODING_FAILED) With the httpie tool a similar error: $ http…
Alex
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Which static file types does Nginx generate ETags for by default?

In modern versions of Nginx, the ETag is automatically generated for static file types, even if you don't specifically enable the etag on in your location blocks or otherwise: https://nginx.org/en/docs/http/ngx_http_core_module.html#etag For…
Jesse Nickles
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Are servers allowed to add a Content-Encoding header based on filename, if there is no compression on-the-fly?

Problem Suppose we have a compressed archive on disk, e.g. file.tar.gz, which should be served as-is. The file is served with Content-Type: application/gzip, but for some reason the server also adds a Content-Encoding: gzip header, even though it…
djvg
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Cannot turn off SSLCompression in Apache?

My Apache is 2.4.46 and is using Openssl version 1.1.1f I have set the directive SSLCompression Off. Even if i enable it, it says SSL Compression is not supported, which is good I guess. But, when I use Firefox to see the webpage's HTTP headers, I…
user549144
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Nginx not setting Vary header via add_header directive in server block?

I have gzip_vary on; I also have (inside a server section): add_header Vary Origin; Yet when I inspect headers sent, the Vary header only includes Accept-Encoding; if I remove the gzip_vary on; line then there is no Vary header emitted at all. I'm…
artfulrobot
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gzip softlocks every midnight during nginx log rotation, causes kernel panic

Some of our servers run on Ubuntu 18.10. They host a few Node.JS services receiving TCP connections as upstream from nginx, as well as a websocket implementation in Dotnet Core. It's a fairly simple setup sysadmin-wise. One of the machines started…
Érik Desjardins
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mysterious gzip malfunction on nginx

· gzip shows as not enabled on my site · and not even the tech support of my host, asmallorange, can figure out the cause of my problem · hopefully someone here can · i've documented my exact set-up (nothing more than this was done) 1) i installed…
abcjme
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How to enable IIS to always precompress / pregzip a certain file?

I have a 4mb js file (gzipped version is 900kb). The file is like this: main.328479fdsdf.js (so it has a hash based on the content). IIS seems to compress my big js file only if is accessed 2 times in 10 seconds. However if I have a user on 3G every…
Alin C
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