# Cache structs 1.6.x vs 1.8.x

**URL:** <https://www.ruby-forum.com/t/cache-structs-1-6-x-vs-1-8-x/243091>\
**Category:** NGINX\
**Created:** [August 20, 2015, 8:36pm UTC](https://www.ruby-forum.com/t/cache-structs-1-6-x-vs-1-8-x/243091 "2015-08-20T20:36:41Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Rafa\_F](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\
**Post date:** [August 20, 2015, 8:36pm UTC](https://www.ruby-forum.com/t/cache-structs-1-6-x-vs-1-8-x/243091/1 "2015-08-20T20:36:41Z")

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Hey Guys,

```
We have been testing Nginx 1.8.x, and We realize that the cache

```

structure for Nginx 1.8.x is not compatible for Nginx 1.6.x. In other  
words,  
by updating Nginx 1.6.x to 1.8.x, all the cache objects will be  
revalidated.  
We are working in a tool to migrate 1.6.x cache objects to 1.8.x in  
order to avoid any cache strike, but We have been having hard time to do  
that. Do you guys know any tool to do such thing ?

Example:

cache struct Nginx 1.6:

Nginx 1.6 Cache object:  
ValidSec: 1447542551 Sat Nov 14 23:09:11 2015  
LastMod: 1438620329 Mon Aug 3 16:45:29 2015  
Date: 1439766551 Sun Aug 16 23:09:11 2015  
CRC-32: 4231235715  
ValidMSec: 0  
HeaderStart: 153  
BodyStart: 536

cache struc Nginx 1.8:

Nginx 1.8 Cache object:  
Version: 3  
ValidSec: 1447759141 Tue Nov 17 11:19:01 2015  
LastMod: 18446744073709551615 Wed Dec 31 23:59:59 1969  
Date: 1439983141 Wed Aug 19 11:19:01 2015  
CRC-32: 1428710042  
ValidMSec: 0  
HeaderStart: 269  
BodyStart: 571  
ETagLen: 0  
ETag:  
VaryLen: 26  
Vary: Accept-Encoding,User-Agent

Thank in advance.

Biazus

Posted at Nginx Forum:

> **[Cache structs 1.6.x vs 1.8.x](https://forum.nginx.org/read.php?2,261151,261151#msg-261151)**
>
> Hey Guys, We have been testing Nginx 1.8.x, and We realize that the cache structure for Nginx 1.8.x is not compatible for Nginx 1.6.x. In other words, by updating Nginx 1.6.x to 1.8.x, all the cache objects will be revalidated. We are working in a...

---

<div class="post-metadata">

**Author:** ![biazus](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/b3f665/32.png) [@biazus](https://www.ruby-forum.com/u/biazus)\
**Post date:** [August 24, 2015, 7:01pm UTC](https://www.ruby-forum.com/t/cache-structs-1-6-x-vs-1-8-x/243091/2 "2015-08-24T19:01:38Z")

</div>

Hi Guys,

We have developed a “cache migration tool” in order to keep the cache  
compatibility between Nginx 1.6.x and 1.8.x.

Comments and suggestions are welcome!

> **[GitHub - acaciocenteno/ngx\_scripts: Simple scripts for viewing and updating...](https://github.com/acaciocenteno/ngx_scripts)**
>
> Simple scripts for viewing and updating Nginx cache - GitHub - acaciocenteno/ngx\_scripts: Simple scripts for viewing and updating Nginx cache

Thanks,  
Biazus

Posted at Nginx Forum:

> **[Re: Cache structs 1.6.x vs 1.8.x](https://forum.nginx.org/read.php?2,261151,261210#msg-261210)**
>
> Hey Guys, We have been testing Nginx 1.8.x, and We realize that the cache structure for Nginx 1.8.x is not compatible for Nginx 1.6.x. In other words, by updating Nginx 1.6.x to 1.8.x, all the cache objects will be revalidated. We are working in a...