MongoDB’s Diversity Scholarship program supports members of groups who are underrepresented in the technology industry. This includes, but is not limited to, people who identify as African American, Hispanic, LGBTQ, women, low-income, and people with disabilities who may not otherwise have the opportunity to attend MongoDB events.
Eligible candidates can apply online. Hurry, the applications close this Friday, April 8!
Diversity Scholarship recipients receive:
- Complimentary admission to MongoDB World
- Complimentary admission to a pre-conference workshop of their choice
- A MongoDB certification voucher
- Three-month access to paid MongoDB University courses
Additionally, scholarship recipients may be featured in a blog post.
Applicants must be 18 years old or older, and must belong to a group that is underrepresented in the technology industry.
Scholarships are awarded based on a combination of need and impact. Selection will be made by a committee that will review each application. All application info will be kept confidential. Recipients will be notified by April 15.
Don’t qualify, but would like to help? You can contribute to the Diversity Scholarship!
While MongoDB World registration is open, we're raising funds to support Diversity Scholarship recipients. There’s a donation opportunity when registering for the conference. Contributors will be listed as Diversity Champions on our website, unless otherwise requested.
Contact firstname.lastname@example.org with any questions.
Running MongoDB as a Microservice with Docker and Kubernetes
Update – November 2018 This post is now 2.5 years old, and neither MongoDB nor Kubernetes have been standing still! In particular, Kubernetes has introduced StatefulSets and we've introduced the MongoDB Enterprise Operator for Kubernetes . Both of these capabilities make working with MongoDB in Kubernetes much simpler and more robust. Read this post for the state-of-the-art in running MongoDB in Kubernetes . Introduction Want to try out MongoDB on your laptop? Execute a single command and you have a lightweight, self-contained sandbox; another command removes all traces when you're done. Need an identical copy of your application stack in multiple environments? Build your own container image and let your development, test, operations, and support teams launch an identical clone of your environment. Containers are revolutionizing the entire software lifecycle: from the earliest technical experiments and proofs of concept through development, test, deployment, and support. Read the Enabling Microservices: Containers & Orchestration Explained white paper . Orchestration tools manage how multiple containers are created, upgraded and made highly available. Orchestration also controls how containers are connected to build sophisticated applications from multiple, microservice containers. The rich functionality, simple tools, and powerful APIs make container and orchestration functionality a favorite for DevOps teams who integrate them into Continuous Integration (CI) and Continuous Delivery (CD) workflows. This post delves into the extra challenges you face when attempting to run and orchestrate MongoDB in containers and illustrates how these challenges can be overcome. Considerations for MongoDB Running MongoDB with containers and orchestration introduces some additional considerations: MongoDB database nodes are stateful. In the event that a container fails, and is rescheduled, it's undesirable for the data to be lost (it could be recovered from other nodes in the replica set, but that takes time). To solve this, features such as the Volume abstraction in Kubernetes can be used to map what would otherwise be an ephemeral MongoDB data directory in the container to a persistent location where the data survives container failure and rescheduling. MongoDB database nodes within a replica set must communicate with each other – including after rescheduling. All of the nodes within a replica set must know the addresses of all of their peers, but when a container is rescheduled, it is likely to be restarted with a different IP address. For example, all containers within a Kubernetes Pod share a single IP address, which changes when the pod is rescheduled. With Kubernetes, this can be handled by associating a Kubernetes Service with each MongoDB node, which uses the Kubernetes DNS service to provide a hostname for the service that remains constant through rescheduling. Once each of the individual MongoDB nodes is running (each within its own container), the replica set must be initialized and each node added. This is likely to require some additional logic beyond that offered by off the shelf orchestration tools. Specifically, one MongoDB node within the intended replica set must be used to execute the rs.initiate and rs.add commands. If the orchestration framework provides automated rescheduling of containers (as Kubernetes does) then this can increase MongoDB's resiliency since a failed replica set member can be automatically recreated, thus restoring full redundancy levels without human intervention. It should be noted that while the orchestration framework might monitor the state of the containers, it is unlikely to monitor the applications running within the containers, or backup their data. That means it's important to use a strong monitoring and backup solution such as MongoDB Cloud Manager , included with MongoDB Enterprise Advanced and MongoDB Professional . Consider creating your own image that contains both your preferred version of MongoDB and the MongoDB Automation Agent . Implementing a MongoDB Replica Set using Docker and Kubernetes As described in the previous section, distributed databases such as MongoDB require a little extra attention when being deployed with orchestration frameworks such as Kubernetes. This section goes to the next level of detail, showing how this can actually be implemented. We start by creating the entire MongoDB replica set in a single Kubernetes cluster (which would normally be within a single data center – that clearly doesn't provide geographic redundancy). In reality, little has to be changed to run across multiple clusters and those steps are described later. Each member of the replica set will be run as its own pod with a service exposing an external IP address and port. This 'fixed' IP address is important as both external applications and other replica set members can rely on it remaining constant in the event that a pod is rescheduled. The following diagram illustrates one of these pods and the associated Replication Controller and service. **Figure 1:** MongoDB Replica Set member configured as a Kubernetes Pod and exposed as a service Stepping through the resources described in that configuration we have: Starting at the core there is a single container named mongo-node1 . mongo-node1 includes an image called mongo which is a publicly available MongoDB container image hosted on Docker Hub . The container exposes port 27107 within the cluster. The Kubernetes volumes feature is used to map the /data/db directory within the connector to the persistent storage element named mongo-persistent-storage1 ; which in turn is mapped to a disk named mongodb-disk1 created in the Google Cloud. This is where MongoDB would store its data so that it is persisted over container rescheduling. The container is held within a pod which has the labels to name the pod mongo-node and provide an (arbitrary) instance name of rod . A Replication Controller named mongo-rc1 is configured to ensure that a single instance of the mongo-node1 pod is always running. The LoadBalancer service named mongo-svc-a exposes an IP address to the outside world together with the port of 27017 which is mapped to the same port number in the container. The service identifies the correct pod using a selector that matches the pod's labels. That external IP address and port will be used by both an application and for communication between the replica set members. There are also local IP addresses for each container, but those change when containers are moved or restarted, and so aren't of use for the replica set. The next diagram shows the configuration for a second member of the replica set. **Figure 2:** Second MongoDB Replica Set member configured as a Kubernetes Pod 90% of the configuration is the same, with just these changes: The disk and volume names must be unique and so mongodb-disk2 and mongo-persistent-storage2 are used The Pod is assigned a label of instance: jane and name: mongo-node2 so that the new service can distinguish it (using a selector) from the rod Pod used in Figure 1. The Replication Controller is named mongo-rc2 The Service is named mongo-svc-b and gets a unique, external IP address (in this instance, Kubernetes has assigned 220.127.116.11 ) The configuration of the third replica set member follows the same pattern and the following figure shows the complete replica set: **Figure 3:** Full Replica Set member configured as a Kubernetes Service Note that even if running the configuration shown in Figure 3 on a Kubernetes cluster of three or more nodes, Kubernetes may (and often will) schedule two or more MongoDB replica set members on the same host. This is because Kubernetes views the three pods as belonging to three independent services. To increase redundancy (within the zone), an additional headless service can be created. The new service provides no capabilities to the outside world (and will not even have an IP address) but it serves to inform Kubernetes that the three MongoDB pods form a service and so Kubernetes will attempt to schedule them on different nodes. **Figure 4:** Headless service to avoid co-locating of MongoDB replica set members The actual configuration files and the commands needed to orchestrate and start the MongoDB replica set can be found in the Enabling Microservices: Containers & Orchestration Explained white paper . In particular, there are some special steps required to combine the three MongoDB instances into a functioning, robust replica set which are described in the paper. Multiple Availability Zone MongoDB Replica Set There is risk associated with the replica set created above in that everything is running in the same GCE cluster, and hence in the same availability zone. If there were a major incident that took the availability zone offline, then the MongoDB replica set would be unavailable. If geographic redundancy is required, then the three pods should be run in three different availability zones or regions. Surprisingly little needs to change in order to create a similar replica set that is split between three zones – which requires three clusters. Each cluster requires its own Kubernetes YAML file that defines just the pod, Replication Controller and service for one member of the replica set. It is then a simple matter to create a cluster, persistent storage, and MongoDB node for each zone. **Figure 5:** Replica set running over multiple availability zones Next Steps To learn more about containers and orchestration – both the technologies involved and the business benefits they deliver – read the Enabling Microservices: Containers & Orchestration Explained white paper . The same paper provides the complete instructions to get the replica set described in this post up and running on Docker and Kubernetes in the Google Container Engine. Interested in learning more about Microservices? Microservices Resources About the Author - Andrew Morgan Andrew is a Principal Product Marketing Manager working for MongoDB. He joined at the start last summer from Oracle where he spent 6+ years in product management, focused on High Availability. He can be contacted @andrewmorgan or through comments on his blog ( clusterdb.com ).
Control Your Colours in MongoDB Charts
Colours are integral to the story you want to convey with any sort of data visualisation. With the latest release of MongoDB Charts , we have added more control to how you can assign colours to your charts! Previously, colour assignment of a series were always based on the series order within that chart. However, we may instead want to colour the chart based on the series value. Some basic scenarios where these different strategies prove useful include: Colouring the top 3 series with the colours gold, silver and bronze. Colouring the series "Summer" and "Winter" with "Red" and "Blue" respectively, to symbolise the season. If the above examples did not give it away enough, we will create some beautiful charts using an Olympics dataset to fully understand the capabilities of the new features. Single-series charts We will start off with a basic single-series chart. These charts usually have a single field encoded to the x and y axes and will display a single colour for the chart. In these charts, we now show a single colour swatch for you to edit. Simple, right? Multi-series charts For more complicated charts with multiple series, we may want to colour the series based on the encoded field itself. These charts are created when multiple fields are encoded to an aggregation channel where the field key is used to build the multi-series chart. In the above chart, I have a medal tally of the top 10 countries based on medal count. The chart itself is fine, but we could improve this chart with some useful colouring! A notable colour scheme we could apply to this chart is assigning each series to the colour of the medal. Inside the Color Palette customisation option, you will see that each encoded field is now listed based on the order that they were encoded in. With the colour scheme set to the medal colour, the chart will be a lot easier to convey the original information. Colours assigned to these channels will always have the same colour assigned and will ignore the ordering of these fields. Assigning chart colours to string data The final chart that we want to create, involves a chart where the data itself is a String type. With these chart types, the Color Palette will provide options to toggle between the two different colour assignment strategies where: 'By Order' will allow you to assign colours by the ordering of the series 'By Series' lets you customise the colour for a specific series value To help streamline the process of assigning colours in the above chart, in the ‘By Order’ menu, I can choose to assign colours based on the value order of the Discipline that appears in the chart. This may be useful if we don't care what the colours are that represent each Discipline. Alternatively, we could assign colours using 'By Series' so that we can be assured that I can represent the Disciplines with an associated colour. Now that we have created all of our charts using the different ways we can assign colours, we can be confident that the colours in our data visualisations are consistent throughout our dashboard. Want to start colouring your charts today? You can start now for free by signing up for MongoDB Atlas , deploying a free tier cluster and activating Charts. Have an idea on how we can make MongoDB Charts better? Feel free to leave an idea at the MongoDB Feedback Engine .