Visualization of Configuration Pushes

This internship project is about a service internal to Google that is responsible for dynamically pushing pieces of configuration or data to running processes.

Motivations

The two main questions this project tries to address are:
1. how do the start and end of all pushes in a push def line up against each other?
2. how does a current push compare against previous pushes?

Terminology

A push definition (push def) describes a particular push. The most relevant information for this project is that a push def describes how a push is split in several stages. At Google, the push defs are organized in a tree hierarchy but, for simplicity, in this project we only used a flat list of push defs.

Each push for a particular push def is identified by a push handle. The handle is composed by joining the name for the push def with a push ID.

For each push there is a push info that describes what happened during a particular push. This includes information about when the push started and when the transition from one stage+state to the next happened.

A push is split in several stages, with each stage updating only a subset of the consumers. Each stage also has an attempt counter associated with it because a stage can be retried several times. Each stage can go through several states before completing.

Bar Chart

The bar chart is a visualization element that helps with the second major question: how does a current push compare against previous pushes, when the number of pushes is not very large?

The bar chart displays the pushes in chronological order, because the pushes happened most recently are probably more important to the user. The y axis of the bar chart is the duration of a single push, with the most common time unit of the pushes. The bar chart consists of a focus bar chart, a compressed bar chart with a selector, and a box plot. The focus bar chart shows a default number of pushes when the user opens the page.

There are several interactive features integrated in the bar chart. The user can use the selector to slide among the bars and select any portion to display. The drop down menu lets the user to switch between all pushes and completed pushes. When the user hovers on a bar or the empty area above it, the bar will be highlighted and a tooltip with the push's pushID, end state, and start time will appear on top of the bar, as well as a tag with the duration of the push.

Box Plot

The bar chart also features a box plot that allows the user to compare the current push duration to the previous pushes and helps the user predict the completion time of an ongoing push. The box plot contains five labels that show the minimum, first quantile(25%), median, third quantile(75%), and maximum duration of the pushes appeared in the focus bar chart.

When the selector updates the focus bar chart or the selection of the drop down menu changes, the box plot will be updated with the new input data. When user hovers over the bar chart, the corresponding data point in the box plot will be highlighted. The points in the box plot will switch to a smaller radius to show the distribution better when there are too many data points.