I am asking a question on what is the way to fix this? when I visit my website I get this:
HTTP Error 503.2 - Service Unavailable
The serverRuntime#appConcurrentRequestLimit setting is being exceeded.
I use IIS on Windows Server 2012, and I have already set Concurrent requests to maximum value? I am pretty sure someone is spamming us with connections, how can this be fixed?
Related
I used cPanel's Transfer Tool to move my websites to a new IP address. It was a temporary move and I wanted to revert back to my old server today. First thing I noticed was the transfer tool changed all the A records for all sites. I changed these back using swapip, and then tried accessing the sites. They load for a very long time and finally fail with:
Service Unavailable The server is temporarily unable to service your
request due to maintenance downtime or capacity problems. Please try
again later.
Additionally, a 503 Service Unavailable error was encountered while
trying to use an ErrorDocument to handle the request.
From numerous threads, I realized 503 usually occurs when System PHP-FPM is on. However, I didn't set this on niether before nor after moving. I didn't change any other settings except the DNS, so I'm guessing it should be a DNS issue, not sure if DNS issues can cause 503 errors. I've been struggling with this for a day now.
Checking Apache Error log, I see attempts to connect to the server I temporarily moved to:
[proxy_http:error] [pid 1659:tid 47454830633216] (110)Connection timed out: AH00957: HTTPS: attempt to connect to [new.ip.address]:443
After a few days digging, I found my mistake and how to rectify it thanks to the cPanel Support. I thought it worthwhile sharing in case anyone else faces the same problem:
First, I had to disable the live transfer feature before doing the transfer. It prevents the tool from disabling IPs and proxying domains.
Given I hadn't I had to rever the changes the tool had made, which basically involved running the following scripts from the command prompt:
$ whmapi1 unset_all_service_proxy_backends username=$USER
$ /scripts/xfertool --unblockdynamiccontent $username
$ whmapi1 unset_manual_mx_redirects domain=domain.tld
The link above explains what each of these scripts does.
I install and config SSRS-2016 on windows server-2012 and IIS-7 everything is good until i restart server or power failure then i get HTTP Error 503. The service is unavailable.i find a alternative solution to solve this.when i change web portal URL and apply changes the problem disappear.how to solve this problem?
after 10 day nobody answer my question.but i find answer
just change SSRS-2016 service from automatic to automatic delay
I am having a trouble using HTTP POST when cloudflare is enabled.
It keeps returning 524 timeout.
Failed to load resource: the server responded with a status of 524 (Origin Time-out)
But when I disabled cloudflare, the HTTP POST works fine.
Any idea what might caused this?
UPDATE
I am using AJAX POST, does this got anything to do with ajax?
Thanks.
General causes for a CloudFlare 524 error.
Support should be able to provide more detailed troubleshooting.
Console utility "netstat" shows that some connections from CloudFlare are in CLOSE_WAIT state. Pointing that server just sits without correctly closing connections. Looking to the TCP traffic of my web server with Message Analyzer, I found several connections that was established and http request was sent but that wasn't ever processed by my server.
So we get an answer: the number of simultaneously established connections outnumbered available Accept() calls. So TCP stack connects and wait while application will handle it's connection. Depending on the situation this can never happen, so the client side just drops this connection after a 30 sec timeout without getting any response.
To fix this, you must increase the number of outstanding possible accepts. This parameter can be named as "Max simultaneous connections number" or something similar. Check your web server documentation \ ask the support to find it out.
Also, as an experiment, you can force your server to reply with the "Connection:close" header to each request. This may prevent reaching the active connections limit problem because CloudFlare keep-alive them just way too long.
Also, the more simultaneous requests you do, the more probability to get in troubles. You can try to set some small webserver-side timeout for idle connections.
P.S.: Illustration of CloudFlare's connections number after one client loaded a page:
(http://i.imgur.com/IgwGLCf.png)
I am running a service on Azure web sites using PHP. From times to times, the server completely stops responding with a 500 HTTP message. So far, I could get these relevant details on the error:
ModuleName: FastCgiModule
Notification: EXECUTE_REQUEST_HANDLER
HttpStatus: 500
HttpReason: Internal Server Error
HttpSubStatus: 0
ErrorCode: The specified network name is no longer available. (0x80070040)
ConfigExceptionInfo:
The only info I was able to find was that this might be a prevention of DoS attack when the server stops executing the scripts (for some limited time?). I solve this now by restarting the server which is not good at all.
As I am unable to find an exact cause of this, I am looking for a better solution than manual restarting or even a hint on how to debug the problem. Thanks
We are connecting to a webdav server through IIS 6 using iPads running iAnnotate. Friday we performed some maintenance where all we really did was pause the virtual server/domain controller where the webdav is setup.
Ever since we did that, we are able to browse the webdav connection from iAnnotate on the iPads but when we try to sync a file back (PUT method I'm assuming) we get an error 411, which actually appears to be error "HTTP Error 401.2 - Unauthorized. You are not authorized to view this page due to invalid authentication headers", according to IIS.
Does anyone have any thoughts or ideas on this?
We figured out what was causing our issue although I may not be able to explain entirely why it mattered.
In IIS there is a setting in the "HTTP Response Headers" under "Set Common Headers" called "Enable HTTP keep-alive". We check marked this option as true and our Windows Authentication started working again.
It seemed to have something to do with the connection not staying open between requests and the application or IIS not realizing the connection was restarted during the SYNC operation.