On loading the file from Apex application, I'm getting the Network Error (tcp_error).
Error Desc: "A Communication error occurred. The Web Server may be down, too busy, or experiencing other problems preventing it from responding to requests. You may wish to try again at a later time".
Please help me in resolving this issue. If increasing the timeout period fixes the issue, please let me know where exactly to do.
I have the same experience before. This might solve your problem. I re-install my Oracle APEX with firewall turn off.
Related
I am working with a customer who is having issues with their GCP Cloud SQL deployment. There questions are transcribed here:
When connecting to Cloud SQL, connections often fail intermittently. This can look like a Python error:
(psycopg2.DatabaseError) server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
Or, in Node, it can look like a timeout error or a socket hang up:
TimeoutError: Knex: Timeout acquiring a connection. The pool is probably full. Are you missing a .transacting(trx) call?
We have everything configured correctly, as far as we can tell, and have followed all the instructions in the Cloud SQL troubleshooting guide. We have an instance with 20GB of memory that should support 250 connections. The timeouts should be set to refresh the connections at the right intervals (< 10 min). So we're not sure what's going on here.
I know that isn't a ton to go on but I wanted to try and do my due diligence in seeing how we can help them. I realize we may not get a perfect answer on what is going on but some additional questions I can ask of them to help debug the issue would be a great help to start with.
I found this similar question that seems to be describing the same issue but it has no answers: PostgreSQL 'Sever closed the connection unexpectedly'
Thanks for any help!
As the error suggest, it's not clear what caused the connection to be closed. I would suggest looking into the Cloud SQL error logs (within your Google Cloud Console) to see detailed information as to why the connection was closed, as it was the case in this Github Issue (The wrong role was assigned).
I've recently moved my memcache server behind an Elastic Load Balancer in AWS. I'm also using Flask-Cache with this memcache. If I'm not mistaken (and it's totally possible I am), Flask-Cache opens a connection to memcache and holds it open. It also appears that the ELB terminates these long-standing connections after some period of time (I think it's about 60 minutes). This will result in errors like:
SomeErrors: error 19 from flush_all: (0x4ff96f0) CONNECTION FAILURE, ::rec() returned zero, server has disconnected
If there was some way I could catch these errors and reconnect (or some magic setting to "try to reconnect on connection failure"), that would solve this problem.
FWIW, I'm using pylibmc, but don't see anything obvious (to me) that I could pass.
Any help would be greatly appreciated!
Being disconnected from ELB is very common and also very difficult to debug. Here are a few things that might help:
Debugging Ideas
Attempt to debug the problem in a staging environment with only one
instance connected to ELB.
Make sure you have application logging with time stamps and that if you catch all exceptions in Python (which is generally not a great idea), that you log the exception. It is possible you have a subtle and hidden bug that appears to be something else if you are catching all exceptions.
Simulate the failure (i.e. manually remove "one" instance from ELB), now look at your logs and make sure you see this manifested in your logs. If you can reproduce the same behavior than you can figure out how to fix it.
Look into a web service automated testing tool like https://loader.io/. This can be very helpful to simulate the conditions when the disconnects appear to happen.
Try the same application with a different load balancer, i.e. HAProxy (I would potentially try this last).
Is it possible that a database (connected to ColdFusion 9 via a datasource connection) being unavailable could cause ColdFusion to become unresponsive? (The database is used for a singular one-off lightly-trafficked app.)
Recently, maintenance on a connected Oracle database (oracle jdbc) has caused that database to be unavailable two different times. Coincidentally, at both these times, ColdFusion pages on our site became unavailable or terribly slow to load (static HTML pages seemed to load fine, for the most part). Restarting the ColdFusion application server service would fix the problem, but only for minutes. The first time, during a time the application server was responsive, we unchecked the "Maintain connections" checkbox. I'm not sure this had any effect, then shortly after the Oracle database came back online, and we didn't seem to have the problem any more.
The second time that database was offline, we experienced a very similar issue with our website - ColdFusion pages becoming reaaaally slow or unavailable altogether. During one of the times when I could access the CF administrator, I updated the datasource and checked "Disable connections". Then I stopped and restarted both the CF ODBC agent and ODBC server services. After that, the problem seemed to stop, but I don't know enough to know if this is causation or coincidence.
Anyone have insights on this?
Server setup: Windows Server 2003 SP2, ColdFusion 9, IIS 6
There are a number of ways to slow a database to a crawl if not stop it completely. If you have hackers for example attacking your database through Port 1433 with attempted logins several times a second that can slow it down and if they get in they can of course do whatever they want. When this happened to me I found a record of attacks in the Event logs; the solution is better network security intercepting such attacks and never letting them actually talk to the database. Or say if your site is vulnerable to SQL injection attacks hackers could be messing with your database that way too but network security wouldn't necessarily work in that case. It doesn't require hackers to degrade the performance of your database however, you could be having a problem with allocated disk space for transaction logs or indexes filling up, or heaven forbid an imminent hardware failure showing early symptoms. You're backing up your database often I hope, off the server. To answer your question yes ColdFusion can and will become unresponsive when pages are called that call the database, and will usually display error messages when the database finally times out and never sends the requested data to ColdFusion. You can protect against that to some extent with CFTRY tags around your queries that display clean and polite error messages instead of ColdFusion's ugly ones if the database fails to return data, at least your site continues to look professional that way. One project I worked used a shared SQL Server database that often got overloaded and slowed down terribly and there was nothing I could do about improving that situation. What I did to keep the site functioning was to maintain a DB backup in the form of a MS Access database (yeah it was inappropriate but it worked when SQL Server wouldn't) and anytime SQL Server failed I had the application set up to automatically use code that called the Access database instead.
These are some ideas for you to think about if you are continuing to have problems, I see nobody's even tried to answer your question in the last six months and that's kinda been my experience with the quality of assistance this site has offered me too. I hope my thoughts can be of some use to you.
I have been struggling with this issue for literally weeks now, but seem to have found a resolution after trying every option on the net. However i'm still at a loss to explain it.
We have a web service with a method that performs a long running SQL query and takes roughly 7 minutes to complete. However, on intermittant runs we get the error;
"The underlying connection was closed: An unexpected error occurred on
a receive."
Now it turns out that in IIS7 it was the Process Model section on the application pool causing this. Even if we set the 'Ping Maximum Response Time' to something like 600 seconds (10 minutes) the error would still appear at random times... sometimes even after only 100 seconds or so.
The only way to stop this error from happening is to set the 'Ping Enabled' feature to false.
I am concerned that this might not be the best way to fix the issue... but the client needs it fixed so this will do for now. Can anyone shed any light on this? We have other sites using older versions of IIS and SQL that do not have this issue. It is only happening on a server running SQL 2008 R2 Express and IIS 7.5.
It is built on the .NET framework v2.0.
Thanks for any insight anyone could give.
An exception occurred when setting up mail server parameters. This
exception was caused by:
coldfusion.mail.MailSpooler$SpoolLockTimeoutException: A timeout
occurred while waiting for the lock on the mail spool directory..
Recently i started to get this nasty exception in my mail.log file. Once this exception shows up, every mail that is sent from that coldfusion instance throws the same exception.
The only thing that seems to work is to restart the coldfusion server. After (usually) a day or two the same exception pops up again and we're back in the same situation.
I am aware of the hotfix to control the mailspool timeout but all it does is increase the timeout from 30 to 60 seconds. Since the mails are sent successfully until i get the exception, i don't think this is my solution.
Also i read the thread in the adobe forum where people have installed the hotfix, but still get the error.
I also tried a script to restart only the mailservice when this exception showed up, but this didn't work for me, as it didn't for others with this problem. This would also not be a concrete solution.
The mails that i send arre simple html mails.
The number of mails sent spreaded over a day is not more then 30.
I've sent mails from
the exact same coldfusion server many times before, but with
<cfmail>. This is the first time i'm sending them in cfscript. I
don't know if this has anything to do with it, but it's only since
i'm using the cfscript equivalent of <cfmail> that i started to get
this exception.
All related blog posts that i could find are all unanswered but also pretty old. I thought that someone might have a solution by now.
Thanks.
(using coldfusion 9.0.1 server on windows 2008 server)
We were also experiencing this mail spool lock issue. After the issue occurred a fourth time in 2 months, we started reviewing these forums and found no solution.
This made me think that perhaps the solution and problem are not really CF at all, so I went into the server's virus protection and excluded the CF mail spool directory so that the virus protection does not touch the spool directory at all. So far, we have not had the problem again.
So I am not sure that this is the permanent fix, but it has worked so far for us. No outside entities create emails within our systems, so the directory should be relatively safe but not having email-outs work is not an option.
this chain from talkingtree might give some light:
http://www.talkingtree.com/blog/index.cfm?mode=entry&entry=67FD4A34-50DA-0559-A042BCA588B4C15B
what they are saying is that it could be an issue with disk activity taking to long. you can increase the mail spool timeout with the jvm argument: -Dcoldfusion.spooltimeout=120
oh.... one more thing. if you're using cfmail to email dumps when an error occurrs, make sure to add 'format="text"' to the cfdump tags. some of the emails can get pretty big and might be causing the error.