AWS Certification Training in Washington USA

Maximizing  MongoDB Performance on AWS

AWS is an incredibly popular environment for running MongoDB deployments. Today you have many choices about instance type, storage, network config, security, how you configure MongoDB processes, and more. In addition, you now have options when it comes to tooling to help you manage and operate your deployment.

• Rely on MongoDB as a service: MongoDB Atlas takes care of the operational heavy lifting so you can focus on building your apps. This is the easiest way to run MongoDB on AWS as many of the recommendations are “built-in”.
• Use management tools designed for MongoDB: Cloud Manager is a powerful management tool that simplifies and automates tasks like monitoring, backups, installation and upgrades, and more.
• Manage everything yourself: if you have an unusual configuration or you want to “roll your own,” there are lots of best practices for running on AWS.

No matter what way you feel is best, this post will help you understand your options and make the most of running MongoDB on AWS. We will discuss several critical factors to consider for optimal performance, including:

• Storage/Disk
• Networking
• Instance Size (Memory and CPU)

Storage

• Databases require fast storage. You wouldn’t expect great performance out of Oracle, MS SQL, or MySQL on a single SATA disk. AWS provides fast storage through Elastic Block Store (EBS) or via Instance Store. EBS are persistent block level storage volumes that you associated to your EC2 instances.
• Instance Stores are storage volumes that directly attach to your EC2 instance hardware, and are designed for temporary storage (i.e. logs, temporary files, scratch space, etc.). EBS is the general type of storage that we recommend for EC2 for MongoDB and we’ll dive into how best to configure it.
• When choosing your disks we have to ask AWS to guarantee our Input/Output Operations Per Second (IOPS) by requesting Provisioned IOPS (PIOPS). In the case of Provisioned IOPS (SSD) volumes, you can provision up to 50 IOPS per GiB. However there is a cap at 20,000 IOPS per volume.
• Amazon’s page on EBS volume types has more information on this subject. In addition, there are EBS-optimized instance types such as the C4, M4, and D2 instance family types. We recommend using this type of instance or enabling this feature for other recommended instance family types such as the R3 or the I2 types.
• EBS-optimized instances provide dedicated throughput between Amazon EC2 and Amazon EBS. This improves performance by minimizing contention from other traffic to your instances with regards to EBS I/O traffic.
• The reason for separating your deployment storage across 3 volumes is that database journal files and log files are sequential in nature, and as such, have different access patterns compared to data files. Separating data files from journal and/or log files, particularly with a write intensive workload, will provide an increase in performance by reducing I/O contention. Depending on your workload, and if you are experiencing high I/O wait times, you may be able to benefit from separate disks for your data files, journal, and log files.

RAID for performance and durability

• There are many levels of RAID, and each has its own advantages and disadvantages. The two key concepts underlying RAID are mirroring (RAID 1) where the same data is written to several disks and striping (RAID 0) where several disks are broken into stripes or bins with the data being copied across these. By using the proper RAID design, data durability and/or increased I/O performance is possible -- sometimes with one being sacrificed for the other. Fortunately, there is a RAID option that doesn’t sacrifice data reliability or increased I/O performance.
• RAID 10 (sometime called RAID 1+0) combines the features of RAID 1 and RAID 0. RAID 1 provides data reliability by mirroring data on secondary drives, whereas RAID 0 helps to increase I/O performance by striping data across drives.
• “In most cases, RAID 10 provides better throughput and latency than all other RAID levels, except RAID 0 (which wins in throughput). Thus, RAID 10 is the preferable RAID level for I/O-intensive applications such as database, email, and web servers, as well as for any other use requiring high disk performance.”
• As noted earlier, you also need to ensure that your total throughput of the combined RAIDed volumes does not exceed the maximum instance throughput. If there are more PIOPS than this maximum limit provisioned for your combined volumes the additional IOPS will be wasted.

Networking

• Because MongoDB can benefit from high packet-per-second performance and lower inter-instance latency networking, Amazon’s Enhanced Networking feature can provide significantly improved performance and consistency.
• If your instance type supports the Enhanced Networking feature, we strongly recommend that you enable it. There are unfortunately a few caveats as Amazon EC2 provides enhanced networking capabilities via single root I/O virtualization (SR-IOV) which is only available on C3, C4, D2, I2, M4, and R3 instances and only supported when you are using Amazon VPC (Virtual Private Cloud).
• Amazon Virtual Private Cloud allows you to provision a private, isolated section in AWS where you can define your own IP address, subnets, route tables, and gateways. Using VPC private subnets when deploying MongoDB servers is recommended. By using Network Address Translation (NAT), your private subnet can access the Internet, but no one on the Internet can access your MongoDB servers.
• AWS provides a Managed NAT (Network Address Translation) Gateway service and we recommend using this. It enables the mapping of your private IP addresses in your VPC private subnet to a public address with traffic leaving AWS, and it then maps any public IP addresses back to your VPC subnet private addresses for traffic entering AWS. It is also possible to configure a site-to-site VPN connection to access your MongoDB deployment.
• With VPC, not only do you get the best networking flexibility, you also get enhanced security features like security groups and access control lists for inbound/outbound filtering. We recommend that you review these security features along with our MongoDB security checklist to ensure your deployment is secure.