Cloud Devops Automation

NewRelic is a great tool to monitor the webapplications , see the insights of the various transactions occurring in the applications and track the code issues. It helps you identify the response times from the different geographical locations and helps you optimize the user experience by  reducing the load times for your applications. If you just want to monitor the website availability you can use the ping monitor of the newrelic. Its simple and don't require any agents configuration upfront and the advantage is that though the traditional monitors monitor for the website http status i.e. 200 for the site loading but won't check if the content is actually loaded or not. This can sometimes cause an issue, while newrelic gives you a functionality where you can monitor the string on the page load and if the newrelic doesn't find that string it would raise an alarm. You can configure the ping for a website as follows, in our example we have simply put the monitor for the ...

In production environment there are always backup scheduled for the entire servers using the AMI or snapshots which take the system backup over a period of time and runs daily in the non peak hours. But there are environments such as non-prod where many people have access to the config so that they can tune this according to there requirements. While this makes things to speed up but since no one is accountable for the changes this can simply go on breaking up the configuration due to multiple changes being performed. Now you can always troubleshoot the changes but sometimes there are situation when the hardware or dns problems might arise which is outside your control. In those cases you can't keep your environment down since this would affect the testing in the lower environments.

You can install the AWS cli using the boto sdk as discussed in my previous post You can also download the aws cli zip package and install the aws cli from it as curl "http://s3.amazonaws.com/aws-cli/awscli-bundle.zip" -o "awscli-bundle.zip"   unzip awscli-bundle.zip   sudo ./awscli-bundle/install -i /usr/local/aws -b /usr/local/bin/aws  

By default the jenkins initiates the builds from the jenkins master. But if you are using the jenkins in an production environment there are chances several builds for different components/ micro services would be required to triggered parallely. In case the IO/Network/System performance for the master may degrade and UI or jenkins might start to give reduced performance , hangs up etc. which is not a desirable state. So its recommended to use the jenkins slave for the builds while master only control those nodes. To add the jenkins slave you need to have the two server's first one is your master server and other one the slave server on which you are going to build the jobs created in the jenkins. For this you require to have 2 servers in our case we are going to use 172.31.59.1 as the jenkins master and 172.31.62.152. You need to install the java jdk on both the servers. For installing java jdk and setting up the environment variables follow my previous posts Java JD...

If you are using the awscli to write your scripts than while checking the ec2 instance id from the instance you might be using the following command wget -q -O - http://169.254.169.254/latest/meta-data/instance-id   The problem is if you are having your server on private subnet and using a proxy to connect to internet and if you use the above command it would give you the proxy server id instead of your instance-id. To overcome this issue use the following while writing your script. export NO_PROXY=169.254.169.254;   The resolves the ip  169.254.169.254  from the instance and does not forward it to the proxy and you would get the instance id of the instance rather than the proxy server.

Error code as noted in Wireshark:- 106   8.721506 0.000024 TCP 172.XX.XXX.XXX -> 172.XX.XX.XXX 368 [TCP segment of a reassembled PDU] 106 Problem statement:- Behind the ELB we were using the HAproxy and sending an options request in which the original request status was replaced by 200 status using the cors configuration. While HAproxy received the request from the ELB and responed back with 200 status ELB was not able to respond back and connection was terminated. Resolution:- After recording the tcpdump and capturing the packets using the pcap file generated and analyzed via the wireshark we noticed the packed 106 was a [TCP segment of a reassembled PDU]. Actually the HTTP Packet is not complete, so the Wireshark is also unable to see the packet as an HTTP valid one, this is the same behavior as the ELB have. According to the RFC-2616, section-6  After receiving and interpreting a request message, a server responds with an HTTP response message. [2]   ...

If you are facing the problems with the webrequest and getting an error status. Than you can monitor the responses on the server side and client side by monitoring the packets sent over the network. You can use the tcpdump for it. If you want to have a greater insight into whats happening over your network than you need to capture the packets and analyze it using the network packet analyzer tool such as wireshark. Else you can use the tcpdump also to view the packets captured. The pcap file needs to generated which captures your packet over the network and is basically a binary file. You need to query that file using the tcpdump or wireshark to see whats happening in your network. To generated the pcap file for monitization use the following command tcpdump -i eth0 -s 65535 -w request.pcap   To analyze the pcap file use the following command tcpdump -qns 0 -X -r request.pcap   you should see the time of the request, Ip from which request was received, your se...

In my previous post i covered the installation of the python pip which can be used for the Botosdk and awscli installation. Follow these steps to install the botosdk and awscli on RHEL in Amazon AWS pip install boto3   pip install awscli This completes the boto3  sdk and awscli installation. Before you can use the command line you need to connect to the aws and authenticate. use the following command for this aws configure   This would in-turn ask your Access key and Secret Access key which you can generate from the AWS IAM. Also you need to enter the region endpoint to ensure you are connecting to correct region in case you are using the multiple regions in AWS and also its a good practice to be followed. Once done you should be able to connect to your AWS environment. 

The RHEL doesn't come with the Awscli or botosdk preinstalled unlike the Amazon Linux. To install the Awscli or python botosdk you need to install the python pip through which you can install the aws cli and boto sdk. But the pip is not installed by default. Follow the following steps to install the python pip on RHEL 7 in Amazon Linux cd /tmp   yum install wget -y wget https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm rpm -ivh epel-release-latest* yum install python-pip This Will complete the installation of the python pip on the RHEL7 Checkout the version of the pip using following command [root@ip-xxx-xx-xx-xxx tmp]# pip -V   pip 7.1.0 from /usr/lib/python2.7/site-packages (python 2.7)