I am doing development work on a site with a strange server set up where sessions basically don't work. It's kind of a long story, but the main crux is it's a cluster of servers that are syncronized from an FTP server every few minutes. And for example, anything written to the filesystem in PHP gets deleted within 5 minutes.
So this means sessions don't work and I get some strange problems in phpMyAdmin, like it forgetting which page of a table I was on - I click 'next page' and end up back at the start again.
I've also tried SQL Buddy and am getting similar problems.
Are there any equivalents that don't use sessions? Doesn't need to be as full-featured as PMA, it's mainly for adding/editing some stuff.
There's always the MySQL GUI Tools.
You can make phpmyadmin use other authentication methods:
http://www.phpmyadmin.net/documentation/#authentication_modes
Depends how much security you need and how restricted you are, but 'config' authentication mode with a custom .htaccess sounds like it might work for you.
I don't know how hard it would be to plug this into phpMyAdmin, but PHP has a functionnality that allows sessions to be stored in another way than using files.
In your case, you already have a database server, obviously, so maybe you could create a "technical" database, and use it to store sessions ? This way, you would still be able use phpMyAdmin (which is quite a good tool), but your problem should be solved.
The PHP function you need to know to do that is session_set_save_handler :
session_set_save_handler() sets the
user-level session storage functions
which are used for storing and
retrieving data associated with a
session.
This is most useful when a
storage method other than those
supplied by PHP sessions is preferred.
i.e. Storing the session data in a
local database.
There are a couple of examples (take a look at the comments at the bottom of the page : some might be helpful)
For instance, Drupal uses this solution to store sessions into DB instead of files, by default.
Another solution would be to use memcached to store your sessions -- of course, if you don't have a memcached server at your disposal, this might be a bit harder than storing them in DB ^^
Or, of course, if you have access to your DB server via the network, you could install phpMyAdmin on your local computer, or use a tool like MySQL GUI Tools and its MySQL Query Browser.
I found a neat solution! SQLBuddy has a feature where you can put the password in the config file and it will use it automatically without a need to log in.
Obviously this is insecure by default, but coupled with a .htaccess and .htpasswd (which does work on the server) I've now got a secure login.
Related
It's been a very long time since I've been on here so I hope I'm doing this properly.
I'm working on a web project that is basically a twitch streamer's profile type of site. It's being designed to display only that streamers information about their stream. So no other users should be logging in via twitch or otherwise.
The problem I'm having is the recent changes to the twitch API requires OAuth to be utilized and the token resets after a period of time as it should.
The question really is this..
How would I go about privately storing a variable on the site? This variable would need to last around 30 - 60 days, not be stored anywhere other than the server, be inaccessible to anyone, and can be changed easily after the time period is up.
I was looking through APC and realized since I'm using php 7.2 that its been replaced with APCU. Reviewing details on APCU there would be problems with that information not being stored for the time frame I need and could possibly just up and get cleared. So that marked that out.
I thought about local file storage but I need to keep the information I'm gathering secret so local file is a nope.
I intend to release the source code once the project is finished so I don't want to use databases as it just makes it more complicated for the simplistic user.
sessions are stored as cookies and that puts the string in the hands of whoever might want to be malicious so thats a nope.
Long story short I'm trying to avoid the following.
local file storage
databases
sessions
any kind of caching that would be unreliable
I just need a step in the right direction.
Sorry about the lengthy post.
If you want minimal setup and infrastructure, sqlite can be a good option. It's still a database but it works within PHP directly and only requires a file to store the data in. This solution is very often used in mobile apps as well so developers can benefit from the power of SQL while keeping it simple for the user.
sqlitetutorial.net has good tutorials to get your started.
I believe I found the solution to the problem. I can still utilize files for the storage and if I place a .htaccess to the directory I wish to restrict with deny from all the server can still access the files and read them accordingly while at the same time restricting outside intrusion.
A little more trickery with some .htaccess and I can just send a 404 response so it looks like there's nothing special there instead of alerting anyone of the files or directories presence.
Thanks to SystemGlitch and imvain2 for making me think more on that problem so I could realize the solution possibilities.
I have a setup where I have a host which routes multiple requests in a load-balanced fashion. My backend uses PHP. Now, I need to use the $_SESSION object for some of my processing.
Will $_SESSION work where I have 3 backend servers which can receive any request at any time?
If not, Can one suggest alternatives to handle such cases?
EDIT: I do understand that we can store sessions in a database and find a way to track it. But, the problem in a realtime load-balanced production scenario is the number of calls that go into a DB. That can be a real bummer for my performance. I'm kind of hoping that, we can handle this at an webserver level.
Not sure, if it is possible, but, if two webservers have some kind of replication mechanism like databases do, it will be brilliant. I dont have to do a thing.
If such a thing does not exist, PHP should be modified to support it. That will actually, make it a seriously robust language.
My Suggestion is to setup PHP to handle the sessions in the database (this way they can all access the session data independent of which server is requesting it).
A good tutorial for that can be found HERE
Look into either memcache (Is it recommended to store PHP Sessions in MemCache?) or REDIS (https://joshtronic.com/2013/06/20/redis-as-a-php-session-handler/).
There is a good tutorial on setting up memcache on Ubuntu at https://www.globo.tech/learning-center/php-memcached-instances-ubuntu-16/. Which also covers using haproxy as a load balancer (although you may already a solution).
Perhaps have a read of https://blog.newtonhq.com/session-handling-for-1-million-requests-per-hour-68cdece15030.
You can store sessions in memcache in order to share session among servers.
Please have a look on documentation here
Hi I have to retrieve data from several web servers. First I login as a user to my web site. After successfull login I have to fetch data from different web servers and display. How can I share a single session with multiple servers. How can I achieve this?
When I first login it create session and session id saved on temp folder of that server. When I try to access another server how can I use current session that already created when I logged in. Can anybody suggest a solution?
You'll have to use another session handler.
You can:
build your own (see session_set_save_handler) or
use extensions that provide their own session handler, like memcached
In complement to all these answers:
If you store sessions in databases, check that garbage collecting of sessions in PHP is really activated (it's not the case on Debian-like distributions, they decided to garbage sessions with their own cron and altered the php.ini so that it never launch any gc, so check the session.gc_probability and session.gc_divisor). The main problem of sessionstorage in database is that it means a lot of write queries and a lot of conflicting access in the database. This is a great way of stressing a database server like MySQL. So IMHO using another solution is better, this keeps your read/write ratio in a better web-database way.
You could also keep the file storage system and simply share the file directory between servers with NFS. Alter the session.save_path setting to use something other than /tmp. But NFS is by definition not the fastest wày of using a disk. Prefer memcached or mongodb for fast access.
If the only thing you need to share between the server is authentification, then instead of sharing the real session storage you could share authentification credentials. Like the OpenId system in SO, it's what we call an SSO, for the web part you have several solutions, from OpenId to CAS, and others. If the data is merged on the client side (ajax, ESI-gate) then you do not really need a common session data storage on server-side. This will avoid having 3 of your 5 impacted web application writing data in the shared session in the same time. Other session sharing techniques (database, NFS, even memcached) are mostly used to share your data between several servers because Load Balancing tools can put your sequential HTTP request from one server to another, but if you really mean parallel gathering of data you should really study SSO.
Another option would be to use memcached to store the sessions.
The important thing is that you must have a shared resource - be it a SQL database, memcached, a NoSQL database, etc. that all servers can access. You then use session_set_save_handler to access the shared resource.
Store sessions in a database which is accessible from the whole server pool.
Store it in a database - get all servers to connect to that same database. First result for "php store session in database"
I am trying to create a more secure PHP sessions login script. Unfortunately for this project I will be working with shared hosting. Would using PHP's session_save_path() function to change the path to something other than /tmp be a secure solution? Or do I need to save the sessions in the database?
Thanks!
Personally, I prefer storing sessions in the database because it not only circumvents some of the file access slowdowns associated with using a file-based system, but also gives you more direct and "supervised" methods of managing the direct session data.
Consider, if you implement using MySQL, using the Memory (HEAP) Storage Engine as it will give enormous performance benefits. This, of course, is assuming you are unlikely to have thousands upon thousands of active sessions, and that your session data is "volatile safe," i.e. if a sever crash causes session data to be lost, the worst that should happen will be that users are asked to log back in.
Moving the session save path is a good start. Just make sure its not in the document root.
With some shared hosted I've observed that getting a database connection can take a second or two. Storing your sessions in the db could slow the whole app down. Your session is accessed twice per page load.
You may want to test both an see which performs better.
OK, so I've got this totally rare an unique scenario of a load balanced PHP website. The bummer is - it didn't used to be load balanced. Now we're starting to get issues...
Currently the only issue is with PHP sessions. Naturally nobody thought of this issue at first so the PHP session configuration was left at its defaults. Thus both servers have their own little stash of session files, and woe is the user who gets the next request thrown to the other server, because that doesn't have the session he created on the first one.
Now, I've been reading PHP manual on how to solve this situation. There I found the nice function of session_set_save_handler(). (And, coincidentally, this topic on SO) Neat. Except I'll have to call this function in all the pages of the website. And developers of future pages would have to remember to call it all the time as well. Feels kinda clumsy, not to mention probably violating a dozen best coding practices. It would be much nicer if I could just flip some global configuration option and Voilà - the sessions all get magically stored in a DB or a memory cache or something.
Any ideas on how to do this?
Added: To clarify - I expect this to be a standard situation with a standard solution. FYI - I have a MySQL DB available. Surely there must be some ready-to-use code out there that solves this? I can, of course, write my own session saving stuff and auto_prepend option pointed out by Greg seems promising - but that would feel like reinventing the wheel. :P
Added 2: The load balancing is DNS based. I'm not sure how this works, but I guess it should be something like this.
Added 3: OK, I see that one solution is to use auto_prepend option to insert a call to session_set_save_handler() in every script and write my own DB persister, perhaps throwing in calls to memcached for better performance. Fair enough.
Is there also some way that I could avoid coding all this myself? Like some famous and well-tested PHP plugin?
Added much, much later: This is the way I went in the end: How to properly implement a custom session persister in PHP + MySQL?
Also, I simply included the session handler manually in all pages.
You could set PHP to handle the sessions in the database, so all your servers share same session information as all servers use the same database for that.
A good tutorial for that can be found here.
The way we handle this is through memcached. All it takes is changing the php.ini similar to the following:
session.save_handler = memcache
session.save_path = "tcp://path.to.memcached.server:11211"
We use AWS ElastiCache, so the server path is a domain, but I'm sure it'd be similar for local memcached as well.
This method doesn't require any application code changes.
You don't mentioned what technology you are using for load balancing (software, hardware etc.); but in any case, the solution to your problem is to employ "sticky sessions" on the load balancer.
In summary, this means that when the first request from a "new" visitor comes in, they are assigned a specific server from the cluster: all future requests for the lifetime of their session are then directed to that server. In practice this means that applications written to work on a single server can be up-scaled to a balanced environment with zero/few code changes.
If you are using a hardware balancer, such as a Radware device, then the sticky sessions is configured as part of the cluster setup. Hardware devices usually give you more fine-grained control: such as which server a new user is assigned to (they can check for health status etc. and pick the most healthy / least utilised server), and more control of what happens when a server fails and drops out of the cluster. The drawback of hardware balancers is the cost - but they are worth it imho.
As for software balancers, it comes down to what you are using. For Apache there is the stickysession property on mod_proxy - and plenty of articles via google to get this working with the php session ( for example )
Edit:
From other comments posted after the original question, it sounds like your "balancing" is done via Round Robin DNS, so the above probably won't apply. I'll refrain from commenting further and starting a flame against round robin dns.
The easiest thing to do is configure your load balancer to always send the same session to the same server.
If you still want to use session_set_save_handler then maybe take a look at auto_prepend.
If you have time and you still want to check more solutions, take a look at
http://redis4you.com/articles.php?id=01..
Using redis you are fault tolerant. From my point of view, it could be better than memcache solutions because of this robustness.
If you are using php sessions you could share with NFS the /tmp directory, where I think the sessions are stored, between all the servers in the cluster. That way you don't need database.
Edited: You can also use an external service like memcachedb (persistent and fast) and store the session info in the memcachedb index and indentify it with a hash of the content or even the session ID.
When we had this situation we implemented some code that lives in a common header.
Essentially for each page we check if we know the session Id. If we dont we check if we're in the situation whehich you describe, by checking if we have stored sesion data in the DB.Otherwise we just start a new session.
Obviously this requires all relevant data to be copied to the DB, but if you encapsulate your session data in a seperate class then it works OK.
you could also try using memcache as session handler
Might be too late, but check this out: http://www.pureftpd.org/project/sharedance
Sharedance is a high-performance server to centralize ephemeral key/data
pairs on remote hosts, without the overhead and the complexity of an SQL
database.
It was mainly designed to share caches and sessions between a pool of web
servers. Access to a sharedance server is trivial through a simple PHP API and
it is compatible with the expectations of PHP 4 and PHP 5 session handlers.
When it comes to php session handling in the Load Balancing Cluster, it's best to have Sticky Sessions. For that ask the network of datacenter who is maintaining the load balancer to enable the sticky session. Once that is enabled you'll don't need worry about sessions at php end