Using postgres adapter not receive message from another server, but successfully with redis adapter,
here my code..
Postgresql Code
Anyone can fix this ??
Expect for close my problem
Related
I'm currently using Heroku auto scale for my servers. And I need to setup a scalable app using socket.io to allow instant updates of data (bear in mind that it's only for updating the frontend displays, no data is processed).
The way I was going to set it up was as follows:
In the image, all the servers have a socket connection to the "main" socket.io server and to the user.
A user would do an action through an API, the server would do its' thing (save to mondoDB or compute...) and pass it to a "main" socket.io server through its socket.io connection but would not send anything back to the user. The "main" server would receive the request through the socket.io connection and emit it back to the servers, which would then emit it to their users.
So the flow would be: User > Server > Main socket.io server > Server > User
My questions are:
Would this work?
Why do all the docs refer to db type redis?
I failed to connect to MySQL from google data fusion
the step:
First, I add the connector
https://dev.mysql.com/downloads/file/?id=462850
Second, I try to add a connection (failed)
screenshot of the MySQL:
Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
**** Edit **** I think this is associated with allowing data fusion to access to our production data
my second question is:
How can I know what is the Google Data Fusion IP address?
if someone can help me that will be wonderful
thank you
This error indicates that Cloud Data Fusion is unable to connect to mysql via JDBC with the given credentials (Host/port/User). You will need to ensure that the user provided can connect from any host. To trouble shoot this further, please do the following:
SSH to the mysql box and run netstat -tln and confirm if the port where mysql is running on is 3306
Login to mysql using Mysql CLI or a workbench tool and run the following
SHOW DATABASES to list all the Databases in mysql and see if the one you are accessing is present
Ensure that the user that is accessing mysql from Data Fusion can access from any hosts by running SHOW GRANTS FOR 'username'#'%'
Here are some additional articles that might help with troubleshooting. https://serverfault.com/questions/89955/unable-to-connect-to-mysql-through-jdbc-connector-through-tomcat-or-externally
Even if you try to access via public IP it'll not work. I had the same issue. Because you have to enable VPC peering between the Datafusion tenant project id with your VPC.
Detailed steps are here: https://cloud.google.com/data-fusion/docs/how-to/create-private-ip
My play framework web application sends automatically emails to user using Apache commons email library, everything works fine on my machine, but when I deploy it on an Ubuntu server it is unable to send email.
It throws exceptions like org.apache.commons.mail.EmailException: Sending the email to the following server failed : smtp.googlemail.com:465 (I also tried different configuration with smtp.google.mail port 465,25 and 587 with or without ssl and tls)
and connection timed out.
I starting to believe that is a problem of some configuration of my ubuntu server.
Any suggestion?
If i type ufw status command I receive status disabled.
Thanks
I am going to close this question, because I found the solution. Basically my Server provider (Scaleway) has a security configuration where SMTP is blocked. I asked them to unlock It.
I was using MySQL Workbench and I am not able to figure out the difference between the following:
1. Server instance
2. Connection to server
In general I want to know if we can use Open Connection to start querying without creating
a server instance of the connection we are trying to connect. Are these two things independent?
You need one or two connections depending on what you wanna do with your server. For MySQL work (i.e. running queries) you need a MySQL connection. For server work (e.g. shutting the MySQL server down or manage other aspects that require shell access) you need a second connection (which is called a Server Instance).
Beginning with MySQL Workbench 6.0 we merged both connection settings into one interface.
I am working on a server/client based project. I almost finished my server side code.
I develop the server app in EclipseCDT on Ubuntu Desktop, and everything just works fine.
But when deploy my app to a Ubuntu Server (I tried Server 10.04/10.10), the server app can start normally (waiting for connection), but the same client just cannot connect to the server.
I use Socket for receiving and sending data to/from the client.
Peter
P.S.: if I install sudo apt-get install ubuntu-desktop on my server machine, then everything works fine again.
===========================================================================
New Findings from the source code:
LabelStartBlocking:
int newScoketId = ::accept(socketId, 0, 0); // socketId == 3 ::accept is define in socket.h
// waiting for connection
LabelResume: // if new connection coming
// Do something with newSocketId
The behavior difference between Ubuntu Desktop and Server is:
On Ubuntu Desktop version, when the server starts, it is blocked at LabelStartBlocking with the socket routine ::accept; and then if a new connection arrives, the server will resume at LabelResume and create a new socket connection using the return value newSocketId;
However, on Ubuntu Server version, when the server starts, it is also blocked at LabelStartBlocking with the socket routine ::accept, but if a new connection arrives, the server won't resume at LabelResume, and the new socket connection CANNOT be created.
Can you guys help me out?
Peter
Thanks for your attention.
I finally figured it out.
If there are more than one IP addresses for the same hostname (/etc/hosts), the old code will fail.
Example /etc/hosts file:
127.0.0.1 localhost YourHostName
10.50.10.251 YourHostName
I traced the calling stack, and I found that, the IP address (10.50.10.251) passed to the program is translated into hostname, and then later the hostname is translated back to IP address (for binding), but a DIFFERENT one, that's why my server program cannot accept any client connection.
Hope it helps if any others have the similar issue.
Peter