Troubleshooting

Here are some problems that you may encounter and some solutions to try.

Running OOM (out of memory)

During bulk loading of data, Dgraph can consume more memory than usual, due to high volume of writes. That’s generally when you see the OOM crashes.

The recommended minimum RAM to run on desktops and laptops is 16GB. Dgraph can take up to 7-8 GB with the default setting --lru_mb set to 4096; so having the rest 8GB for desktop applications should keep your machine humming along.

On EC2/GCE instances, the recommended minimum is 8GB. It’s recommended to set --lru_mb to one-third of RAM size.

You could also decrease memory usage of Dgraph by setting --badger.vlog=disk.

Too many open files

If you see an log error messages saying too many open files, you should increase the per-process file descriptors limit.

During normal operations, Dgraph must be able to open many files. Your operating system may set by default a open file descriptor limit lower than what’s needed for a database such as Dgraph.

On Linux and Mac, you can check the file descriptor limit with ulimit -n -H for the hard limit and ulimit -n -S for the soft limit. The soft limit should be set high enough for Dgraph to run properly. A soft limit of 65535 is a good lower bound for a production setup. You can adjust the limit as needed.