I am new in Symfony2 and I am working in a project in the prod environment.
I changed a twig file so it looks like I have to clean the cache to update the page.
There is any risk at cleaning the cache of the project?
It is possible that I am going to lost any important file?
If yes, there is a way to make this update of some safer way?
Short answer: yes, it can be dangerous. No, there's no safer way. You should take a backup of the whole application root (cache included).
Details
The cache folder contains "compiled" files. Unless someone is doing something very wrong, it does not contains important files. And - even if it does - it would probably be quite complex to get them out from cache.
So at first glance you should be able to delete the cache anytime you want without fear.
Cache version
There's a small catch: you cannot be sure that - even before your changes - the current cache is sync with the current source code.
If, previously, someone made changes to the application but did not clear the cache, those changes are not actually used in production.
In this case, when you clear the cache all such changes will be released as well as your change.
Suggestion
Right now the only way is forward, so you have to clear the cache. But you may want to:
backup first
get a list of more recent changes to source code
do the task when you have time to test and fix if something comes up
In the long term, you should use a deploy script / system to make sure that the cache is automatically cleared any time some changes to source code is delivered.
Related
I'm experimenting with enabling the shared cache in a SQLite implementation I'm working on. In the actual app everything works fine, but my unit tests are now failing with "disk I/O error"s. I'm assuming this is because the shared cache is making assumptions about the file that are no longer valid once it's been deleted.
How can I clear out this shared cache data? I've tried running sqlite3_shutdown() followed by sqlite3_initialize() but the problems persist.
I've actually discovered that some of my tests weren't closing connections properly, and that was the source of my problem - shared-cache was just highlighting it (though I'm not 100% sure why).
That said, in my journey, I did manage to find a way to control where SQLite puts its temporary files. the sqlite3_temp_directory global variable lets you define it - by default it's blank and defers to the OS, I think.
If you set that directory you can manually clear out any files whenever you wish.
Until now I have been using the standard "assets.version" configuration directive for the versioning of my assets. I am releasing a new production quite frequently (once a week or more). So if I change a single asset (e.g. javascript file), I increment my "version counter".
Here is my problem with this system: Changing a single line in an asset causes the invalidation of all assets of the whole application! This means that every weeks, users connecting to my application will re-download all assets! This appear to be quite inefficient to me...
My Question: is there a smarter system? for example we could imagine a console command to execute before each release that would track changes of every assets (using e.g. md5) and save the version to be used for every single asset? This way, only modified assets would be re-downloaded...
I know I can develop my own service and use assets.version_strategy like in this example But, before re-inventing the wheel, I would like to know if nothing similar already exists? It seams to me that every one should be using such a solution...
Thank you!
Vincent
Everything I have read so far, it seems as though you copy the DB from assets to a "working directory" before it is used. If I have an existing SQLite DB I put it in assets. Then I have to copy it before it is used.
Does anyone know why this is the case?
I can see a possible application to that, where one doesn't want to accidentally corrupt database during write. But in that case, one would have to move database back when it's done working on it, otherwise, next time program is run will start from "default" database state.
That might be another use case - you might always want to start program execution with known data state. Previous state might be set from external application.
Thanks everyone for your ideas.
I think what I might have figured out is that the install cannot put a DB directly to the /data directory.
In Eclipse there is no /data which is where most of the discussions I have read say to put it.
This is one of the several I found:
http://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/comment-page-4/#comment-37008
Our code is in SVN. We develop using Visual Studio and the AnkhSVN plugin.
Having used VSS before SVN I was used to the idea of locking files so other users know not to edit it while you are (in fact I thought this was the main point of source control, to prevent lost data from these conflicts).
I've been told this rarely happens and cases where you can't work because another dev is locking you out are more frequent (which sounds like a principle that might only apply to a certain subset of dev projects). But anyway, SVN is better and we're using it.
So when I do edit a file, and go to check it in, and find out the other user has edited it too, what do I actually do?
Surely there's a better way than saving a copy of my file, reverting changes, updating it from server, then merging my changes back in with winmerge? When I right-click the file and click 'merge' I'm told I should update first, so that's obviously not what I need.
.
Update: partial answer
OK, it sounds like I just hit update, then SVN merges non-conflicting changes automatically, and should let AnkhSVN know about any conflicting changes to allow some kind of resolution. Does anyone know how this works in AnkhSVN - what I'd actually do?
(if not I'll try it myself, accept the current top answer and update this question with the second half for posterity).
Actually, that's exactly what you need.
Edit: Clarification, what you need to do is just hit that update. You don't need to make a separate copy, revert, etc. Updating from the repository will merge those changes with your own.
When you do the update, where you have local changes to a file that has also been changed in the repository, SVN will merge the file in the repository with your local file, preserving both sets of changes.
In effect, it should do what you would do with Winmerge automatically.
If the changes are conflicting, typically that they occur within the same lines, there will be a merge conflict, which has to be resolved. Not knowing AnkhSvn, I don't know what it will do in this case, but it should have some means of fixing things. Usually it involves looking over 3 files (your local file, the repository file, and the result of a successful merge) where you pick each part you want to keep from the two changed versions of the file.
After you've updated your local copy, merged and fixed any conflicts, you commit as usual.
It´s not an direct answer to your question, but I would recommened to use SVN-Monitor in addition to AnkhSVN or any other Subversion client like TortoiseSVN.
With it you can watch your repository and will be notified by changes in your repository. So you can see what other devs did in the repository and probably see if your commit will conflict with other checkins or if you can update your local copy without any effect/conflict
I never know what to do when my Wordpress installation tells me there's an update available. I am using version 2.8 so whenever there is an update, all I have to do is click update, some magic happens behind the scenes, and it gets updated. But should I create backup files? And how? I have custom themes and plugins that I don't want to get lost because I don't have backups! Is it safe to assume that nothing bad will happen when you click the upgrade button? What is your process when you decide to upgrade to the newest version?
Backup the database, wp-content directory and configuration files first.
There are plug-ins to make this easier, but since you're asking on StackOverflow, I'll assume you could write a script to do it yourself. While you're at it, add the script as a cron job.
http://codex.wordpress.org/WordPress_Backups#Backup_Resources
Always backup before making a big change like that.
You'll want to copy all your files to a safe place via FTP. Copy 'em, zip 'em up, and keep them somewhere safe where you can remember where they are. You'll also want to backup or "export" the database and keep that also safe. This way if something goes wrong, you can restore it to the way it was.
There's a good backup script here for Wordpress sites:
http://www.guyrutenberg.com/2008/05/07/wordpress-backup-script/
based on Bash and bzip2.
I usually don't update nothing in production without testing it first, unless is a simple modification and is about security (like the 2.8.4 update).
The ideal thing to do is create a separate installation to be a test server: can be in your local machine, or just a whole different installation in your server. Why? Remember you have plugins installed and some may break, updating everything can't be a "blind" decision!
So, before updating in the production installation/server, always test in the "test environment".
Nothing is worse than having your website down because of an update error.