I created MySQL database in RDS of AWS, and successfully connected it from MySQL workbench and Spring Boot application. However, it only works for the 10 to 20 minutes. Then, I can't connect to it anymore.
If I delete the database and create a new one, same problem will happen. It only works in the beginning. Although I haven't changed anything since I created the databases, it still stopped being connectable.
What can be possibly causing it.
Can you check the security group attached to RDS. If you specify a rule to access from specific IP address/address space. Maybe the IP has changed
Reference - RDS Security Groups
Related
We use Azure SQL Database, and therefore had to jump through some hoops to get cross-database queries set up. We achieved this following this great article: https://techcommunity.microsoft.com/t5/azure-database-support-blog/cross-database-query-in-azure-sql-database/ba-p/369126 Things are working great for most of our databases.
The problem comes in for one of our databases which is read-only. The reason it's read-only is b/c it is being synced from another Azure SQL Server to derive its content. This is being achieved via the Geo-Replication function in Azure SQL Database. When attempting to run the query GRANT SELECT ON [RemoteTable] TO RemoteLogger as seen in the linked article, I of course get the error "Failed to update because the database is read-only."
I have been trying to come up with a workaround for this. It appears user permissions are one of the things that do NOT sync as part of the geo-replication, as I've created this user and granted the SELECT permission on the origin database, but it doesn't carry over.
Has anyone run into this or something similar and found a workaround/solution? Is it safe/feasible to temporarily set the database to read/write, update the permission, then put it back to read-only? I don't know if this is even possible - I was told by one colleague that they think it will throw an error along the lines of "this database can't be set to read/write b/c it's syncing from another database..."
I figured out a work-around: Create a remote connection to the database on the ORIGIN server. So simple, yet it escaped me until now. Everything working great now.
I Created SQL Server Database in Azure which is serverless and tried to access it using my SQL Server Management Studio in my local but I couldn't get it work.
It always gives me this message:
I tried to whitelist also my IP in Azure but still I get the same result.
Is there a possible way to make it connect?
Is the database currently online or paused?
I'll repeat the text from #David Browne's link:
If a serverless database is paused, then the first login will resume the database and return an error stating that the database is unavailable with error code 40613. Once the database is resumed, the login must be retried to establish connectivity. Database clients with connection retry logic should not need to be modified.
So;
Assuming the database is paused, this is normal operation
Please read docs
You need to retry after the database starts OR manually pre-start it using the Powershell provided in the link below
https://learn.microsoft.com/en-us/azure/sql-database/sql-database-serverless#connectivity
And yes, you also need to whitelist your IP address as you have already done.
Obviously this flavour of SQL is unsuitable for some types of applications - there is more information in the link - I suggest you read the whole thing.
I'm using the AWS Toolkit in Visual Studio 2013 to attempt to launch a new instance on Amazon RDS. I get through the wizard for creating the new instance and after clicking finish, there is a delay, and then a message appears saying:
Error launching DB instance: DB Security Groups can only be associated with VPC DB Instances using API version 2012-01-15 through 2012-09-17.
Launching different types of instances (SQL Server SE vs MySQL) doesn't seem to help, nor does selecting different versions of the platforms (SQL Server 2008 vs 2012). The only thing that gets it to go through is unchecking the box for "default" in the DB Security Groups area. However, I feel like something is going on here that shouldn't be happening.
Can anyone explain why this is happening and how I can resolve it other than by not setting a default security group? Thank you.
If you created your AWS account recently, you will be using a VPC by default.
It sounds like the API the plugin is trying to use hasn't been updated. The latest version is 1.5.6, and looking at the history it seems like some of these features were added in 1.5.0.
I finally solved it! Since I couldn't use the API that the VS 2013 plugin uses, I had to manually add my IP to the Security Group created for my Elastic Beanstalk.
Go to the console, ec2's security groups configuration
Find the one which description matches your Beanstalk (e.g.: Security Group created for Beanstalk Environment to give access to RDS instances)
Hit Inbound, Edit and add a new rule for All Traffic (I guess HTTP should be enough, but just in case).
In Source, select My IP and Save.
Context: The Cloud
We have a java-based web application that we normally host on our own servers. Recently we used Amazon Web Services (AWS EC2) cloud to host an instance.
This "cloud setup" matches our typical "on site" setup: one server for the app server, another server for the database server. (Several app servers point to the same database server)
The problem
In this cloud setup, we receive intermittent "connection reset by peer errors" between the database and the jdbc driver, where at (seemingly) random intervals and at random points in the codebase, the database connection fails.
Here are a few error excerpts for the log
Stack Trace Example 1:
at com.participate.pe.genericdisplay.client.taglib.GenDisplayViewTag.doStartTag(GenDisplayViewTag.java:77)
... 75 more
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The connection is closed.
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:170)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.checkClosed(SQLServerConnection.java:304)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.getMetaData(SQLServerConnection.java:1734)
at org.jboss.resource.adapter.jdbc.WrappedConnection.getMetaData(WrappedConnection.java:354)
Stack Trace Example 2
at java.lang.Thread.run(Thread.java:619)
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: Connection reset
at com.microsoft.sqlserver.jdbc.SQLServerConnection.terminate(SQLServerConnection.java:1368)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.terminate(SQLServerConnection.java:1355)
at com.microsoft.sqlserver.jdbc.TDSChannel.read(IOBuffer.java:1532)
at com.microsoft.sqlserver.jdbc.TDSReader.readPacket(IOBuffer.java:3274)
at com.microsoft.sqlserver.jdbc.TDSCommand.startResponse(IOBuffer.java:4437)
at com.microsoft.sqlserver.jdbc.TDSCommand.startResponse(IOBuffer.java:4389)
at com.microsoft.sqlserver.jdbc.SQLServerConnection$1ConnectionCommand.doExecute(SQLServerConnection.java:1457)
at com.microsoft.sqlserver.jdbc.TDSCommand.execute(IOBuffer.java:4026)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(SQLServerConnection.java:1416)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectionCommand(SQLServerConnection.java:1462)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.setAutoCommit(SQLServerConnection.java:1610)
at org.jboss.resource.adapter.jdbc.BaseWrapperManagedConnection.checkTransaction(BaseWrapperManagedConnection.java:429)
Technical Environment
Jboss 4.2.2.GA (Jboss-Web 2.0/ Tomcat 6)
MSSQL 2005 2.0 jdbc driver
Some points
We have never seen this problem in
our own environment (i.e. own data centers) running the application for several years
This led me to conclude "something funny is going on with Amazon network environment". I may be wrong/missing something/etc.
This problem only occurs with our application. We have other java and php applications which have not had this problem. The other java application uses a different jdbc driver (jtds, afaik)
It doesn't seem like a simple connection timeout
Questions
-Has anyone seen this before?
-If it's an EC2 "known issue", can we configure our way around the problem (i.e. make sure everything is on its own subnet or virtual private cloud (vpc) ?
-Any jdbc driver settings to get past this problem?
** Update **
I've extended and increased the bounty on this question.
On extra bit of information: the two virtual servers (database and application server) were on different subnets--i.e. one hop between the two servers.
In a non-cloud environment we have "zero hops" bewtewn the two servers.
Our hosting admins said we had no control over the subnets of our EC2 instances. This made me wonder if virtual private cloud would help.
thanks in advance
will
Not sure if this is related or not. We experienced something similar with an app that we were running in the EC2 environment. Same symptom, that the database connection would intermittently close. We were using MSSQL 1.2 driver. Also, we would see the errors usually after a delay or idle time with the connection. Our assumption (never proven) was that something in the network layer was closing the connection and the client wasn't detecting it, so it became stale.
We were able to work around it because we were using commons connection pools, and had the pool recreate the connection on failure. We eventually moved the application out of EC2 and didn't see the issue again.
Just a word of caution on usind DBCP/connection pool features to mitigate the issue - the more you enable 'testOnBorrow' and other features, the more you can introduce latency or other performance changing affects on the system. I don't know if DBCP still does this or not, but a few years ago it would generate actual test queries to test the connection - full stack, database responses - not just at the network layer. The above link from Brian brings back horrific memories from the early 2000s on surrounding re-try logic for JDBC connection management.
Anyway, it's tough to really root cause this, other than gather evidence and eliminate the 'seemingly random' to a specific set of conditions:
You could try to throw up a Wireshark/PCAP trace, find when it happens, and send the results to both Amazon and Microsoft to see if they can root cause it
You could try the above with certain test harnesses to isolate the problem (JMeter tests to get concurrency up), bounce the network connection, watch for recovery, etc
You could try alternative versions of SQL Server to discount a SQL Server/JDBC driver bug that has since been fixed.
If DNS is used in connection strings, could use IP addresses to validate nslookup issues
I'm not a SQL Server expert, but another route for research could be within the related products domain - e.g. see if anyone experienced similar issues with TFS/Sharepoint (e.g. such as http://nickhoggard.wordpress.com/2009/12/07/further-experiences-with-tfs-2010-beta-2-on-amazon-ec2/ )
I have seen this issue in both the EC2 environment and the Windows Azure environment. I think connection retry logic needs to be a standard part of your design when working in a distributed computing environment.
This article is for SQL Azure - but I think it equally applies to EC2 and all drivers.
I can also confirm that this happens and will spin up a lower priority investigation since it's not production critical.
Our production servers are in our data center. We use developer laptops to run our applications. Neither of these get this issue once we configured c3p0 connection pool timeouts and test period (see article: http://www.codefin.net/2007/05/hibernate-and-mysql-connection-timeouts.html).
However, we do have a development staging server that is in EC2 and it does indeed happen there. If I find something that seems to work, I'll ping back. Also, I'm using mysql. I see that you are using MS SQL Server so it is across database vendors.
ActiveDirectory Server 2003
I am using the ActiveDirectoryMembershipProvider and ADroleProvider. They work great. Until my active directory server restarts in the middle of the day to get updates. (I'm not in charge of the server and can't change this). When this happens, for the five minutes the server is rebooting, my users can't use my website because I've tied my menu to the Role Provider. So, here are my questions:
Is it possible to tell my RoleProvider to use the "next" available ADS? If so, how so that while the initial one reboots, I don't frustrate my users with ADS connection messages?
Should I be using some kind of connection pool that automatically reconnects to the available server? If so, how?
Let's imagine that all my active directory servers go down. Is there a way to keep my web application running? Obviously there are bigger problems if all servers are down, but what I'm after is a possible "disconnected" active directory authentication that will still move forward if the server somehow goes kaput. Is this wise AND possible?
You probably have the server connection string set to "server01.domain.local". If you change it to just "domain.local" you're no longer depending on "server01" being online. Instead you will use the Round Robin feature of Active Directory DNS to get a list of all domain controllers and use one that's online. (I don't think your admins reboot all of the domain controllers at the same time...)
Also try running nslookup domain.local a couple of times in succession in a command prompt to see the order changing.