Glow is currently mostly functioning, yet still very small. It is actually pretty similar to Spark, but written in Go. Spark was once touted as small in 2012, of about 14K lines of code. So I did a source code line count for Glow (March 5th, 2016). Excluding empty lines and comments:

API and Standalone Execution , folder “flow”, 1670 lines

and , folder “flow”, 1670 lines Master for scheduling, folder “resource”, 955 lines.

for scheduling, folder “resource”, 955 lines. Agent for execution and data storage, folder “agent”, 515 lines.

for execution and data storage, folder “agent”, 515 lines. Driver for distributed execution, folder “driver”, 2162 lines.

for distributed execution, folder “driver”, 2162 lines. Network , folder “netchan”, 654 lines.

, folder “netchan”, 654 lines. Hadoop Source , folder “source/hdfs”, 62 lines.

, folder “source/hdfs”, 62 lines. glow.go file, 111 lines.

file, 111 lines. Utility tools, folder “util”, 463 lines.

Examples, folder “examples”, 472 lines.

Including examples, Glow has total 7064 lines. So Glow is still smaller than the small, about half size of Spark in 2012. Of course, the feature sets are different and totally not comparable. Glow still have room to add more features. Welcome to try it and add your feature!