Using session->set_flashdata causes 502 Bad gateway error - php

I am getting 502 bad gateway error when ever I use
$this->session->set_flashdata('message', 'Profile updated.');
I am using CodeIgniter on nginx. The code runs fine on localloast(WAMP). If I comment out the lines, application runs fine.
Any help will be appreciated.

in application/config/config.php set "use_database" to TRUE

I figured out what was wrong. First of all, a colleague with more server knowledge explained me that my setup probably was such that nginx received all the requests, and then directly served static files. for non-static request, it passed on the work to apache, and serves as an intermediary. So probably something went wrong when apache tried to send data to nginx (or when nginx tried to send information to apache).
As I never worked with nginx before, I also did not think of checking the nginx log files. And there was an error that I could use:
[error] 27453#0: *9223 upstream sent too big header while reading response header from upstream, client:
I ended up applying the first bit of this other stack overflow solution:
Add this to your nginx.conf file normally located at
Code:
/etc/nginx/nginx.conf:
proxy_buffer_size 128k;
proxy_buffers 4 256k;
proxy_busy_buffers_size 256k;
By the way, it should be added to the http section of the file. That was something what was missing from the solution.
Reference:
https://forum.codeigniter.com/archive/index.php?thread-59675.html

from #sasho 's answer
$config['sess_use_database'] = TRUE;
By changing into database you can move session data to database's table to avoid permission related problems. Try and reply here.
https://www.codeigniter.com/user_guide/libraries/sessions.html
You can see the database driver section from the official documentation to avoid these kind of errors.

Related

(failed)net::ERR_HTTP2_PROTOCOL_ERROR AJax erorr [duplicate]

I'm currently working on a website, which triggers a net::ERR_HTTP2_PROTOCOL_ERROR 200 error on Google Chrome. I'm not sure exactly what can provoke this error, I just noticed it pops out only when accessing the website in HTTPS. I can't be 100% sure it is related, but it looks like it prevents JavaScript to be executed properly.
For instance, the following scenario happens :
I'm accessing the website in HTTPS
My Twitter feed integrated via https://publish.twitter.com isn't loaded at all
I can notice in the console the ERR_HTTP2_PROTOCOL_ERROR
If I remove the code to load the Twitter feed, the error remains
If I access the website in HTTP, the Twitter feed appears and the error disappears
Google Chrome is the only web browser triggering the error: it works well on both Edge and Firefox.
(NB: I tried with Safari, and I have a similar kcferrordomaincfnetwork 303 error)
I was wondering if it could be related to the header returned by the server since there is this '200' mention in the error, and a 404 / 500 page isn't triggering anything.
Thing is the error isn't documented at all. Google search gives me very few results. Moreover, I noticed it appears on very recent Google Chrome releases; the error doesn't pop on v.64.X, but it does on v.75+ (regardless of the OS; I'm working on Mac tho).
Might be related to Website OK on Firefox but not on Safari (kCFErrorDomainCFNetwork error 303) neither Chrome (net::ERR_SPDY_PROTOCOL_ERROR)
Findings from further investigations are the following:
error doesn't pop on the exact same page if server returns 404 instead of 2XX
error doesn't pop on local with a HTTPS certificate
error pops on a different server (both are OVH's), which uses a different certificate
error pops no matter what PHP version is used, from 5.6 to 7.3 (framework used : Cakephp 2.10)
As requested, below is the returned header for the failing ressource, which is the whole web page. Even if the error is triggering on each page having a HTTP header 200, those pages are always loading on client's browser, but sometimes an element is missing (in my exemple, the external Twitter feed). Every other asset on the Network tab has a success return, except the whole document itself.
Google Chrome header (with error):
Firefox header (without error):
A curl --head --http2 request in console returns the following success:
HTTP/2 200
date: Fri, 04 Oct 2019 08:04:51 GMT
content-type: text/html; charset=UTF-8
content-length: 127089
set-cookie: SERVERID31396=2341116; path=/; max-age=900
server: Apache
x-powered-by: PHP/7.2
set-cookie: xxxxx=0919c5563fc87d601ab99e2f85d4217d; expires=Fri, 04-Oct-2019 12:04:51 GMT; Max-Age=14400; path=/; secure; HttpOnly
vary: Accept-Encoding
Trying to go deeper with the chrome://net-export/ and https://netlog-viewer.appspot.com tools is telling me the request ends with a RST_STREAM :
t=123354 [st=5170] HTTP2_SESSION_RECV_RST_STREAM
--> error_code = "2 (INTERNAL_ERROR)"
--> stream_id = 1
For what I read in this other post, "In HTTP/2, if the client wants to abort the request, it sends a RST_STREAM. When the server receives a RST_STREAM, it will stop sending DATA frames to the client, thereby stopping the response (or the download). The connection is still usable for other requests, and requests/responses that were concurrent with the one that has been aborted may continue to progress.
[...]
It is possible that by the time the RST_STREAM travels from the client to the server, the whole content of the request is in transit and will arrive to the client, which will discard it. However, for large response contents, sending a RST_STREAM may have a good chance to arrive to the server before the whole response content is sent, and therefore will save bandwidth."
The described behavior is the same as the one I can observe. But that would mean the browser is the culprit, and then I wouldn't understand why it happens on two identical pages with one having a 200 header and the other a 404 (same goes if I disable JS).
In my case it was - no disk space left on the web server.
For several weeks I was also annoyed by this "bug":
net :: ERR_HTTP2_PROTOCOL_ERROR 200
In my case, it occurred on images generated by PHP.
It was at header() level, and on this one in particular:
header ('Content-Length:'. Filesize($cache_file));
It did obviously not return the exact size, so I deleted it and everything works fine now.
So Chrome checks the accuracy of the data transmitted via the headers, and if it does not correspond, it fails.
EDIT
I found why content-length via filesize was being miscalculated: the GZIP compression is active on the PHP files, so excluding the file in question will fix the problem. Put this code in the .htaccess:
SetEnvIfNoCase Request_URI ^ / thumb.php no-gzip -vary
It works and we keep the header Content-length.
I am finally able to solve this error after researching some things I thought is causing the error for 24 errors. I visited all the pages across the web. And I am happy to say that I have found the solution.
If you are using NGINX, then set gzip to off and add proxy_max_temp_file_size 0; in the server block like I have shown below.
server {
...
...
gzip off;
proxy_max_temp_file_size 0;
location / {
proxy_pass http://127.0.0.1:3000/;
....
Why? Because what actually happening was all the contents were being compressed twice and we don't want that, right?!
The fix for me was setting minBytesPerSecond in IIS to 0. This setting can be found in system.applicationHost/webLimits in IIS's Configuration Editor. By default it's set to 240.
It turns out that some web servers will cut the connection to a client if the server's data throughput to the client passes below a certain limit. This is to protect against "slow drip" denial of service attacks. However, this limit can also be triggered in cases where an innocent user requests many resources all at once (such as lots of images on a single page), and the server is forced to ration the bandwidth for each request so much that it causes one or more requests to drop below the throughput limit, which causes the server to cut the connection and shows up as net::ERR_HTTP2_PROTOCOL_ERROR in Chrome.
For example, if you request 11 GIF images all at once, and each individual GIF is 10 megabytes (11 * 10 = 110 megabytes total), and the server is only able to serve at 100 megabytes per second (per thread), the server will have to slow the throughput on the last GIF image until the first 10 are finished. If the throughput on that last GIF is slowed so much that it drops below the minBytesPerSecond limit, it will cut the connection.
I was able to resolve this by following these steps:
I used Chrome's Network Log Export tool at chrome://net-export/ to see exactly what was behind the ERR_HTTP2_PROTOCOL_ERROR error. I started the log, reproduced the error, and stopped the log.
I imported the log into the log viewer at https://netlog-viewer.appspot.com/#import, and saw an interesting event titled HTTP2_SESSION_RECV_RST_STREAM, with error code 8 (CANCEL).
I did some Googling on the term "RST_STREAM" (which appears to be an abbreviated form of "reset stream") and found a discussion between some people talking about an IIS setting called minBytesPerSecond (discussion here: https://social.msdn.microsoft.com/Forums/en-US/aeb01c46-bcdf-40ed-a417-8a3558221137). I also found another discussion where there was some debate about whether minBytesPerSecond was intended to protect against slow HTTP DoS (slow drip) attacks (discussion here: IIS 8.5 low minBytesPerSecond not working against slow HTTP POST). In any case, I learned that IIS uses minBytesPerSecond to determine whether to cancel a connection if it cannot sustain the minimum throughput. This is relevant in cases where a single user makes many requests to a large resource, and each new connection ends up starving all the other unfinished ones, to the point where some may fall below the minBytesPerSecond threshold.
To confirm that the server was canceling requests due to a minBytesPerSecond error, I checked my server's HTTPERR log at c:\windows\system32\logfiles\httperr. Sure enough, I opened the file and did a text search for "MinBytesPerSecond" and there were tons of entries for it.
So after I changed the minBytesPerSecond to 0, I was no longer able to reproduce the ERR_HTTP2_PROTOCOL_ERROR error. So, it appears that the ERR_HTTP2_PROTOCOL_ERROR error was being caused by my server (IIS) canceling the request because the throughput rate from my server fell below the minBytesPerSecond threshold.
So for all you reading this right now, if you're not using IIS, maybe there is a similar setting related to minimum throughput rate you can play with to see if it gets rid of the ERR_HTTP2_PROTOCOL_ERROR error.
I experienced a similar problem, I was getting ERR_HTTP2_PROTOCOL_ERROR on one of the HTTP GET requests.
I noticed that the Chrome update was pending, so I updated the Chrome browser to the latest version and the error was gone next time when I relaunched the browser.
I encountered this because the http2 server closed the connection when sending a big response to the Chrome.
Why?
Because it is just a setting of the http2 server, named WriteTimeout.
I had this problem when having a Nginx server that exposing the node-js application to the external world. The Nginx made the file (css, js, ...) compressed with gzip and with Chrome it looked like the same.
The problem solved when we found that the node-js server is also compressed the content with gzip. In someway, this double compressing leading to this problem. Canceling node-js compression solved the issue.
I didn't figure out what exactly was happening, but I found a solution.
The CDN feature of OVH was the culprit. I had it installed on my host service but disabled for my domain because I didn't need it.
Somehow, when I enable it, everything works.
I think it forces Apache to use the HTTP2 protocol, but what I don't understand is that there indeed was an HTTP2 mention in each of my headers, which I presume means the server was answering using the right protocol.
So the solution for my very particular case was to enable the CDN option on all concerned domains.
If anyone understands better what could have happened here, feel free to share explanations.
I faced this error several times and, it was due to transferring large resources(larger than 3MB) from server to client.
This error is currently being fixed: https://chromium-review.googlesource.com/c/chromium/src/+/2001234
But it helped me, changing nginx settings:
turning on gzip;
add_header 'Cache-Control' 'no-store, no-cache, must-revalidate, proxy-revalidate, max-age=0';
expires off;
In my case, Nginx acts as a reverse proxy for Node.js application.
We experienced this problem on pages with long Base64 strings. The problem occurs because we use CloudFlare.
Details: https://community.cloudflare.com/t/err-http2-protocol-error/119619.
Key section from the forum post:
After further testing on Incognito tabs on multiple browsers, then
doing the changes on the code from a BASE64 to a real .png image, the
issue never happened again, in ANY browser. The .png had around 500kb
before becoming a base64,so CloudFlare has issues with huge lines of
text on same line (since base64 is a long string) as a proxy between
the domain and the heroku. As mentioned before, directly hitting
Heroku url also never happened the issue.
The temporary hack is to disable HTTP/2 on CloudFlare.
Hope someone else can produce a better solution that doesn't require disabling HTTP/2 on CloudFlare.
In our case, the reason was invalid header.
As mentioned in Edit 4:
take the logs
in the viewer choose Events
chose HTTP2_SESSION
Look for something similar:
HTTP2_SESSION_RECV_INVALID_HEADER
--> error = "Invalid character in header name."
--> header_name = "charset=utf-8"
By default nginx limits upload size to 1MB.
With client_max_body_size you can set your own limit, as in
location /uploads {
...
client_max_body_size 100M;
}
You can set this setting also on the http or server block instead (See here).
This fixed my issue with net::ERR_HTTP2_PROTOCOL_ERROR
Just posting here to let people know that ERR_HTTP2_PROTOCOL_ERROR in Chrome can also be caused by an unexpected response to a CORS request.
In our case, the OPTIONS request was successful, but the following PUT that should upload an image to our infrastructure was denied with a 410 (because of a missing configuration allowing uploads) resulting in Chrome issuing a ERR_HTTP2_PROTOCOL_ERROR.
When checking in Firefox, the error message was much more helpful:
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://www.[...] (Reason: CORS header ‘Access-Control-Allow-Origin’ missing). Status code: 410.
My recommendation would be to check an alternative browser in this case.
I'm not convinced this was the issue but through cPanel I'd noticed the PHP version was on 5.6 and changing it to 7.3 seemed to fix it. This was for a WordPress site. I noticed I could access images and generic PHP files but loading WordPress itself caused the error.
Seems like many issues may cause ERR_HTTP2_PROTOCOL_ERROR: in my case it was a minor syntax error in a php-generated header, Content-Type : text/plain . You might notice the space before the colon... that was it. Works no problem when the colon is right next to the header name like Content-Type: text/plain. Only took a million hours to figure out... The error happens with Chrome only, Firefox loaded the object without complaint.
If simply restarting e.g., Chrome Canary, with a fresh profile fixes the problem, then one surely
is the "victim" of a failed Chrome Variation! Yes, there are ways to opt out of being a Guinea pig in Chrome's field testing.
In my case
header params can not set null or empty string
{
'Authorization': Authorization //Authorization can't use null or ''
}
I got the same issue (asp, c# - HttpPostedFileBase) when posting a file that was larger than 1MB (even though application doesn't have any limitation for file size), for me the simplification of model class helped. If you got this issue, try to remove some parts of the model, and see if it will help in any way. Sounds strange, but worked for me.
I have been experiencing this problem for the last week now as I've been trying to send DELETE requests to my PHP server through AJAX. I recently upgraded my hosting plan where I now have an SSL Certificate on my host which stores the PHP and JS files. Since adding an SSL Certificate I no longer experience this issue. Hoping this helps with this strange error.
I also faced this error and I believe there can be multiple reasons behind it. Mine was, ARR was getting timed-out.
In my case, browser was making a request to a reverse proxy site where I have set my redirection rules and that proxy site is eventually requesting the actual site. Now for huge data it was taking more than 2 minutes 5 seconds and Application Request Routing timeout for my server was set to 2 minutes. I fixed this by increasing the ARR timeout by below steps:
1. Go to IIS
2. Click on server name
3. Click on Application Request Routing Cache in the middle pane
4. Click Server Proxy settings in right pane
5. Increase the timeout
6. Click Apply
My team saw this on a single javascript file we were serving up. Every other file worked fine. We switched from http2 back to http1.1 and then either net::ERR_INCOMPLETE_CHUNKED_ENCODING or ERR_CONTENT_LENGTH_MISMATCH. We ultimately discovered that there was a corporate filter (Trustwave) that was erroneously detecting an "infoleak" (we suspect it detected something in our file/filename that resembled a social security number). Getting corporate to tweak this filter resolved our issues.
For my situation this error was caused by having circular references in json sent from the server when using an ORM for parent/child relationships. So the quick and easy solution was
JsonConvert.SerializeObject(myObject, new JsonSerializerSettings { ReferenceLoopHandling = ReferenceLoopHandling.Ignore })
The better solution is to create DTOs that do not contain the references on both sides (parent/child).
I had another case that caused an ERR_HTTP2_PROTOCOL_ERROR that hasn't been mentioned here yet. I had created a cross reference in IOC (Unity), where I had class A referencing class B (through a couple of layers), and class B referencing class A. Bad design on my part really. But I created a new interface/class for the method in class A that I was calling from class B, and that cleared it up.
I hit this issue working with Server Sent Events. The problem was solved when I noticed that the domain name I used to initiate the connection included a trailing slash, e.g. https://foo.bar.bam/ failed with ERR_HTTP_PROTOCOL_ERROR while https://foo.bar.bam worked.
In my case (nginx on windows proxying an app while serving static assets on its own) page was showing multiple assets including 14 bigger pictures; those errors were shown for about 5 of those images exactly after 60 seconds; in my case it was a default send_timeout of 60s making those image requests fail; increasing the send_timeout made it work
I am not sure what is causing nginx on windows to serve those files so slow - it is only 11.5MB of resources which takes nginx almost 2 minutes to serve but I guess it is subject for another thread
In my case, the problem was that Bitdefender provided me with a local ssl certificate, when the website was still without a certificate.
When I disabled Bitdefender and reloaded the page, the actual valid server ssl certificate was loaded, and the ERR_HTTP2_PROTOCOL_ERROR was gone.
In my case, it was WordPress that now requires PHP 7.4 and I was running 7.2.
As soon as I updated, the errors disappeared.
Happened again and this time it was the ad-blocker that didn't like the name of my images (yt.png, ig.png, url.png). I added a prefix and all loaded ok.
In my case, the time on my computer (browser client) was out of date, synced it using settings in windows, and then the error got away
I had line breaks in my Content-Security-Policy in my nginx.conf that produced this error when used in an docker container running in Kube in GCP (serving angular but I doubt that matters).
Putting them all back on the same line and the problem went away.
A curl -v helped diagnose.
http2 error: Invalid HTTP header field was received: frame type: 1, stream: 1, name: [content-security-policy], value: [script-src 'unsafe-inline' 'self....
It was much easier to edit on separate lines but never again!

Nginx reporting upstream sent too big header while reading response header from upstream

I am running a php-fpm application behind nginx, and sometimes I am getting 502 responses with the message "upstream sent too big header while reading response header from upstream". I have read lots of posts saying that the solution is to increase the fastcgi_buffers configuration, however I have increased this from fastcgi_buffers 16 64k; all the way to fastcgi_buffers 8 256k; and I still see the issue.
What I would like to know is, how can I try and debug and figure out what exactly is causing the issues. I have access to the nginx access and error logs, but I am not sure what to look for to try and find out why the specific endpoints in question are causing this issue.

Docker nginx server returns 302 to HTTP POST: proxy then fails

I have a fairly simple Docker setup whereby a jwilder/nginx-proxy container sits above an nginx container which listens to a php_fpm.
All seems well until the website attempts an HTTP POST (for a password). The nginx server returns a HTTP 302 response. The next request, for the subsequent "dashboard," gets HTTP 499. The proxy layer says: "upstream timed out while reading response header from upstream."
Strangely enough, looking at the logs of the actual application-FPM container, I see no reference whatsoever to anything but index.php!
(This is strictly a "developer machine" environment ...)
Thoughts?
As I also answered elsewhere, this is how it turned out:
The login dialog does an HTTP POST to /login
The proxy server got the request, but wound up timing-out hence the 502.
The nginx server found that the FPM server process apparently died, resulting in a 499 code. (But apparently the Proxy didn't get that ...)
The php-FPM server produced nothing in its own log-files. No indication that it ever even got the /login request in the first place, and no indication whatever why it died.
What did it turn out to be? A problem connecting with a back-end database server. But, finding that out was pure guesswork.
For me this worked out...So ths issue was that I had made a mistake with the rewrite configuration for default nginx configuration file. To sort you out stackoverflow style.
Look for this line
try_files ...
below it add this rewrite regex in condition
if (!-e $request_filename){
rewrite ^/(.*)$ /index.php;
}
adapted from this article from Digital Ocean
https://www.digitalocean.com/community/questions/unexpected-302-error-moved-temporarily-after-login-in-my-website

Laravel gives 502 error upon validation failure form submit

I have an update form, which updates my database with the given inputs. I use the Laravel validation to make an update validator to check if the given e-mail is unique or not (if it's not it should throw me the validation error and reload the update page).
This is my validator:
public function rules()
{
$contact_guid = $this->route('contact_guid');
return [
'contact_email' => [
Rule::unique('contact')->ignore($contact_guid, 'contact_guid'),
],
];
}
public function messages()
{
return [
'contact_email.required' => 'E-mail is required.',
'contact_email.unique' => 'This e-mail is already in use.',
];
}
The problem appears to be that some contacts give the 502 error with certain unique emails and other contacts get the 502 error on different unique emails. I've noticed that once I remove 'contact_email.unique' => 'This e-mail is already in use.', that my application works fine and it doesn't give me the 502 error.
Edit:
I found that how longer the message is at 'contact_email.unique' => 'This e-mail is already in use.',, it gives me the 502 bad gateway more often.
In my case it happened due to nginx not being configured to deal with big headers, I saw this in the logs:
upstream sent too big header while reading response header from upstream
The solution was to add these lines to the nginx configuration:
fastcgi_buffers 16 16k;
fastcgi_buffer_size 32k;
A HTTP 502: Bad Gateway response is not one that would by default be output by Laravel, but would be output by your server:
The HyperText Transfer Protocol (HTTP) 502 Bad Gateway server error response code indicates that the server, while acting as a gateway or proxy, received an invalid response from the upstream server.
It is entirely possible that the invalid response however is stemming from your application, and so would make sense to make an attempt at debugging it.
There are potentially a wider number of causes for such a problem, here is a brief overview of them and potential fixes:
Ensure you have debug enabled in your Laravel .env file and have cleared the cache.
File Permissions are incorrectly set. Should be (depending on server but general rule of thumb) 644 for files and 755 for folders/directories.
An error in one of the PHP Files - Try enabling the display_errors option in your PHP configuration.
PHP Memory & Process limitations - Try increasing your memory_limit in your PHP configuration.
Other PHP Process Limitations - Check with server admin/hosting provider
Corrupt PHP Modules, Extensions, Builds - Check with server admin/hosting provider
The obscure - If points 1-6 don't produce a fix typically the best course of action is to check the Apache Error Logs.
TL;DR: You need to have your Network/System Administrator identify the cause of the HTTP 502. Apache Error Logs will likely give you a very good indication.
I had the same issue. Increasing the buffer size fixed it. Moreover, I was using cookies as the session driver in my app, I guess the ~1kb session cookie was taking up all the buffer?
Changed session driver to file/database fixed the issue as well

Drupal + Nginx + Php-cgi : 502 Bad Gateway error

We are running Drupal 5.x on Nginx with php-fastcgi.
Things were working fine for a while. All of a sudden, we (users) are running into 502 Bad Gateway error.
Restarting PHP-cgi, nginx.. rebooting machine etc did not help.
Did anyone else run into this type of issue? What are the possible suspects?
Today I was getting “502 Bad Gateway” on a CI project , after digging into the problem I found out it is a problem of nginx fastcgi buffers , here is how to fix it :
open /etc/nginx/nginx.conf
add the following lines into http section :
fastcgi_buffers 8 16k;
fastcgi_buffer_size 32k;
502 errors are usually caused when PHP freaks out for some reason. The first thing you should do is check all of your logfiles. That includes system stuff in /var/log/ and the nginx logs.
If you haven't made any recent changes and the problem just started happening for no apparent reason, PHP may be running out of memory. I know when it happens as an Apache module it gives a blank screen--wouldn't be surprised if a 502 error happened under nginx and the FastCGI interface. That's easy to fix by putting ini_set('memory_limit', '256M') into your index.php and see if that fixes the problem.
Also, can you load stand alone PHP files that don't involve Drupal? Put putting <?php phpinfo(); ?> into a file called info.php and try hitting that and see what happens.
Good luck!
I got this error as well and I eventually disable all modules (non-core) and enable them one by one to see what caused the error.
Here's a easy way to disable all non-core modules.
If the problem just started.. Read above.. if the server is new just setup, try this command to see if it's even listening on it's port
netstat -lpn | grep ":9000"
If course you could have setup fast-cgi to work on a different port, so just replace the port 9000 in that statement with what ever port you're looking for.. If nothing continues to show up, likely nothing is listening on that port and you need to fix that problem first.
If you have firePHP disable it.
Big headers causes problems while nginx comunication with php
Usually when I have come across this it has been a fatal error in PHP somewhere. Have a look at your PHP-cgi log to see if it is in there. There should be something in the nginx log like this: 104: Connection reset by peer. Depending on your setup this (sorry, link dead) might help but if you're using php-fpm it won't.
increase your memory limit and it will be fixed. ini_set('memory_limit', '256M');
It is because you probably upgraded to PHP 5.5 and therefore you now are using opcode cache which you may have enabled twice. That is check php.ini and also opcache.ini.

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