CZLB is disabled by default on NLB and GLB and is enabled by default on the ALB. Essentially the function of CZLB is how your load balancer distributes traffic among AZs. If you have you have CZLB enabled then the traffic is distributed evenly across all instances regardless of AZ. If it is disabled traffic…
Posts/Projects
Post #94 (AWS) – Sticky Session (Session Affinity)
With your load balancer in AWS you may run into an issue where you need to be able to have the user consistently connect to the same application they’ve connected to previously to ensure that session data is not lost, that is where Sticky sessions come in. A sticky session allows one client to connect…
Post #93 (AWS) – Gateway Load Balancer
The Gateway Load Balancer, or GLB, is the final load balancing option in AWS. It operates on layer 3 and it has a very important function. You use the GLB to forward traffic to other network devices, such as firewalls, IPS, IDS, etc. The traffic enters the load balancer, goes to the appropriate target groups…
Post #92 (AWS) – Network Load Balancer
Next up in terms of Load Balancers in AWS is the Network Load Balancer. This operates on layer 4 utilizing TCP and UDP in order to forward traffic. A NLB is a high performance load balancer that can handle millions of requests per second with ~100 millisecond delay. You create target groups just like with…
Post #91 (AWS) – Application Load Balancer
An Application Load Balancer, or ALB, is different from a CLB as it allows you to have one LB for multiple applications rather than needing a different LB for each one. It operates on layer 7 and traffic can be divided based on target groups which can either be a set of instances, a set…
Post #90 (AWS) – Classic Load Balancer (Deprecated)
The first load balancer type is actually one that is no longer with us. It came out in 2009 and operates on layer 4 and 7 of the OSI model. It is the simplest of the load balancers and simply balances traffic to EC2 instances across multiple AZ evenly, unless you opt for crozz-zone load…
Post #89 (AWS) – The Elastic Load Balancer
The Elastic Load Balancer, or ELB, is AWS’s managed load balancing offering. You simply create your load balancer from a variety of load balancer types, classic load balancer, application load balancer, network load balancer, or gateway load balancer. I will go into more detail on the differences between these types in a later post. In…
Post #88 (AWS) – Amazon EFS
EFS, or Elastic File system is a powerful alternative to EBS. If an EBS is a network drive, then EFS is a NFS that can be accessed by multiple instances ACROSS DIFFERENT AZ utilizing NFS v4.1. It is only available with linux based AMI, not windows. It scales up along side your usage and you…
Post #87 (AWS) – EBS encryption
EBS encryption is generally a no-brainer. When you create the volume you have the option to enable encryption. It will encrypt your data at rest, it will encrypt any snapshots taken of the volume, and all data sent between your EC2 instance and the volume is encrypted using KMS AES-256. If you have a volume…
Post #86 (AWS) – EBS multi-attach
Normally you can only attach one EBS volume to one instance. Well if you have an EC2 instances using io1/io2 volume type you can enable multi-attach. This allows you to connect up to 16 EC2 instances in the same AZ to one EBS volume using your high throughput io1/io2 volume. You must use a cluster…