I am trying to learn basics of blockchain by trying the multichain platform, I have been following multichain guide to make a private blockchain, I am using two instances of EC2, I managed to create a blockchain using my first instance :
>multichaind secondChain -daemon
MultiChain Core Daemon build 1.0 alpha 27 protocol 10007
MultiChain server starting
Looking for genesis block...
Genesis block found
Other nodes can connect to this node using:
multichaind secondChain#XXX.XX.X.XX:XXXX
Node started
However, when I try to connect to the blockchain using a second instance of EC2, I am getting rejected :
>multichaind secondChain#XXX.XX.X.XX:XXXX
MultiChain Core Daemon build 1.0 alpha 27 protocol 10007
Retrieving blockchain parameters from the seed node XXX.XX.X.XX:XXXX ...
Error: Couldn't connect to the seed node XXX.XX.X.XX on port XXXX - please check multichaind is running at that address and that your firewall settings allow incoming connections.
Which is kind of expected, as I need to grant connect rights to that machine. However, It should return me a wallet address so I can grant the connection rights.
I think this is related to EC2 settings that are probably not allowing me to connect. I have few knowledge of EC2 and networks in general. I can't figure this out.
Have you checked if the access to the port is granted on the instance you're trying to connect?
If multichaind says "please check multichaind is running at that address and that your firewall settings allow incoming connection"
It is usually one or the other. Port and Running already.
Since you havent yet granted, its probably port.
Related
I'm trying to connect my local standalone MySQL with Cloud Fusion to create and test a data pipeline. I have deployed the driver successfully.
Also, I have configured the pipeline properties with correct values of jdbc string, user name and password but connectivity isn't getting established.
Connection String: jdbc:mysql://localhost:3306/test_database
I have also tried to test the connectivity via data wrangling option but that is also not getting succeeded.
Do I need to bring both the environments under same network by setting up some VPC and tunneling?
In your example, I see that you specified localhost in your Connection String. localhost is only advertised to other services running local to your machine, and Cloud Data Fusion (running in GCP) will not be able to reach the MySQL instance (running on your machine). Hence you're seeing the connectivity issue.
I highly recommend looking at this answer on SO that will help you setup a quick proof-of-concept.
I think that your question is more related to the way how to connect some on-premise environments to GCP networking system that gathering Google cloud instances or resources throughout VPC connection model.
Admitting the fact that GCP is actually leveraging different approaches for connection methods within a Hybrid cloud concepts, I would encourage you to learn some fundamental principles of Cloud VPN as a essential part of performing secure connection between particular VPN Peer Gateway and Cloud VPN Gateway and further creating a VPN tunnel between parties.
I guess there is even dedicated chapter in GCP documentation about Data Fusion VPC peering implementation that might be helpful in your user case.
I’ve now tried to create a serverless Aurora (MySQL compatible) database and connect to it for two days, and I just can’t seem to get it to work. Supposedly I should have been able to get it up and running in five minutes.
In any case, I created am Aurora Serverless database in the US East (N. Virginia) region (us-east-1), and have been able to connect to it with the AWS Query Editor. I also have an EC2 server in the same region, and have given the Aurora database the same security group (under RDS > Security Group), and in the security group I have opened for MYSQL/Aurora (TCP, 3306) from all sources. When I click the modify button on the database, there is also another (VPC) Security Group listed (rds-launch-wizard-4), which was created automatically. This one I also located under my EC2 dashboard and gave access to all ports from all sources (inbound), and to all ports (outbound). And there is a networking VPC & subnet group, which I don’t know what to do with, if anything.
I try to connect to the database, using this command line command:
mysql -h hest2.cluster-xxxxx.us-east-1.rds.amazonaws.com -P 3306 -u root –p
It generates an error “ERROR 2003 (HY000): Can't connect to MySQL server on” on both my EC2 instance, my local computer and on other online servers.
From the EC2 instance, try doing a telnet on the DB port to test if all your security group settings are applied correctly.
telnet hest2.cluster-xxxxx.us-east-1.rds.amazonaws.com 3306
If the connection does go through, then the issue is with your client code. Cross check that you have wired the right endpoint in your code.
If the telnet connection does not group (I'm guessing that it would not), then it is guaranteed that your security group settings are not set correctly. In order to debug this further, we would need more details on:
The list of vpc security groups associated with your cluster.
The details of each of these vpc security groups (You've mentioned that
you've opened up everything, but I'd like to see the exact rules in
place)
As for laptop and other servers - If they are outside the VPC, then it would not work. Aurora Serverless is accessible only from within the VPC as of now.
I'm trying to install oracle on AWS redhat instance. Follow the steps given on this url: http://www.davidghedini.com/pg/entry/install_oracle_11g_xe_on And when I run config command as follows
/etc/init.d/oracle-xe configure
It gives following error.
Database Configuration failed. Look into
/u01/app/oracle/product/11.2.0/xe/config/log for details
When I check the log files it shows following errors.
ORA-01034: ORACLE not available Process ID: 0 Session ID: 0 Serial
number: 0
It seems specific issue on AWS cloud instance.
Is it because of swap memory?
Or is it because of port issue?
I'm using micro instance on it.
How can I get through?
this might be an EC2 security group issue and outbound access to the network on some port being used by the installer (license check, maybe?).
if your EC2 instance is very tightly locked down, you could test if it's a security group issue by adding a new Outbound security group rule to allow all TCP traffic out to anywhere on the internet (0.0.0.0/0)
for example, the install might be trying to hit a remote licensing server endpoint via HTTP or HTTPS but your security group doesn't allow that traffic out.
perhaps there's a 'verbose' flag that you can run the installer with that can give you more info about what it's failing on? HTH
I had a running instance, and then I became unable to connect to it via http(80) and ssh(22). I tried to reboot the instance, but nothing went up. This has happened to me twice in the past month.
Why does it happen? Can I do anything to fix and/or prevent it from happening?
If I launch a new instance in same region, and it works.
Things to check when trying to connect to an Amazon EC2 instance:
Security Group: Make sure the security group allows inbound access on the desired ports (eg 80, 22) for the appropriate IP address range (eg 0.0.0.0/0). This solves the majority of problems.
Public IP Address: Check that you're using the correct Public IP address for the instance. If the instance is stopped and started, it might receive a new Public IP address (depending on how it has been configured).
VPC Configuration: Accessing an EC2 instance that is launched inside a Virtual Private Cloud (VPC) requires:
An Internet Gateway
A routing table connecting the subnet to the Internet Gateway
NACLs (Network ACLS) that permit through-traffic
If you are able to launch and connect to another instance in the same subnet, then the VPC configuration would appear to be correct.
The other thing to check would be the actual configuration of the operating system on the instance itself. Some software may be affecting the configuration so that the web server / ssh daemon is not working correctly. Of course, that is hard to determine without connecting to the instance.
If you are launching from a standard Amazon Linux AMI, ssh would work correctly anytime. The web server (port 80) would require installation and configuration of software on the instance, which is your responsibility to maintain.
I am using Amazon EC2 services & and its working correctly but suddenly from 3-days before when we try to access our instance using ssh connection we got following error:
"ssh: connect to host ec2----***.compute-1.amazonaws.com port **: Connection timed out"
when I try to access our sites deployed on our EC2 instance, I received the same error ,
"The connection has timed out
The server at ec2----***.compute-1.amazonaws.com is taking too long to respond"
there is no problem in network connection from our side as we are able to access other web site and services smoothly.
I can't even able to access hosted site without this.
I encountered the same problem.
I followed the troubleshooting in http://alestic.com/2010/05/ec2-move-ebs-boot-instance
Then when I tried to start a new instance, I got an message from Amazon:
Server.InsufficientInstanceCapacity: We currently do not have sufficient m1.small capacity in the Availability Zone you requested (us-east-1b). Our system will be working on provisioning additional capacity. You can currently get m1.small capacity by not specifying an Availability Zone in your request or choosing us-east-1d, us-east-1c, us-east-1a.
Maybe, you have an instance is us-east-1b, too.
You can try to access the System Console (either via the amazon web console or elasticfox) and check for any errors/messages that might help you arrive at the cause of this.
In ~/.ssh/config, add the following lines:
ServerAliveInterval 50
This will keep on pinging the server every 50 seconds to keep the connection alive.