Skip to main content

FAQ

General

What is special about JBrowse 2

One thing that makes JBrowse 2 special is that we can create new view types via our plugin system, e.g. circular, dotplot, etc. Anything you want can be added as a view, and can be shown alongside our other views

This makes JBrowse 2 more than just a genome browser-- it is really a platform that can be built on.

What are new features in JBrowse 2

See the https://jbrowse.org/jb2/features page for an overview of features

Setup

What web server do I need to run JBrowse 2

JBrowse 2 by itself is just a set of JS, CSS, and HTML files that can be statically hosted on a webserver without any backend services running.

Therefore, running JBrowse 2 generally involves just copying the JBrowse 2 folder to your web server html folder e.g. /var/www/html/.

If you use a different platform such as Django, you may want to put it in the static resources folder.

Note that the server that you use should support byte-range requests (e.g. the Range HTTP header so that JBrowse can get small slices of large binary data files.

BAM files do not work on my server

If you are using Apache then you will probably want to disable mime_magic. If mime_magic is enabled, you may see that your server responds with the HTTP header Content-Encoding: gzip which JBrowse does NOT want, because this instructs the browser to unzip the data but JBrowse should be in charge of this.

How can I setup JBrowse 2 on my web server

We recommend following the steps in the quickstart web guide.

The general procedure is using the jbrowse create /var/www/html/jb2 and this will download the latest version of jbrowse to your web folder e.g. in /var/www/html

You can also use jbrowse upgrade /var/www/html/jb2 to get the latest version

How do I install or update the @jbrowse/cli tool

To install the @jbrowse/cli tool, you can use npm install -g @jbrowse/cli

You can use this same command to upgrade the tool too

This command will give you a command named jbrowse which should automatically be in your path if you have a standard installation of nodejs. We recommend using nodesource or nvm to get your nodejs for this.

Also note that the @jbrowse/cli tool is just made for preparing your config.json, it is not used to run any server-side code

How do I update my instance of jbrowse-web

You can use the command, after installing

jbrowse upgrade /path/to/your/jbrowse2

This will download the latest release from github and overwrite it onto your jbrowse-web instance

How can I setup JBrowse 2 without the CLI tools

The jbrowse CLI tools are basically a convenience, and are not strictly required

Simple tasks can be done without it

For example, for jbrowse create, you can visit the blog and download the latest jbrowse-web release tag, and unzip it into your web directory

For other things, like add-assembly and add-track, you can manually edit the config.json, reviewing the config docs and sample configs will be valuable

Understanding the config basics will come in handy also because you can manually edit in advanced configs after your tracks are loaded however be careful because corrupt configs can produce hard to understand errors, because our config system is strongly typed

Feel free to message the team if you encounter these

How do I load a track into JBrowse 2

If you have followed the above steps and installed jbrowse 2 on your webserver and loaded the assembly, and have the CLI tools installed

jbrowse add-track myfile.bw -a hg19

This will setup a bigwig track on the hg19 assembly in your config.json. Make sure to run the command inside your current jbrowse2 folder e.g. /var/www/html/jbrowse2 or wherever you are currently setting up a config.json (you can have multiple configs)

Note that you can also use remote URLs

jbrowse add-track http://yourremote/myfile.bam

The add-track command will do as much as possible to infer from the file extension how to configure this track, and automatically infer the index to be myfile.bam.bai

Curiosities

Why do all the tracks need an assembly specified

We require that all tracks have a specific genome assembly specified in their config. This is because jbrowse 2 is a multi-genome-assembly browser (and can compare genomes given the data). This may be different to using say jbrowse 1 where it knows which genome assembly you are working with at any given time

How are the menus structured in the app

In JBrowse 1, the app level menu operated on the single linear genome view, but with JBrowse 2, the top level menu only performs global operations and the linear genome view has it's own hamburger menu. Note that each track also has it's own track level menu.

Why do some of my reads not display soft clipping

Some reads, such as secondary reads, do not have a SEQ field on their records, so they will not display softclipping.

The soft clipping indicators on these reads will appear black.

Text searching

Why I am running out of disk space while trix is running

The jbrowse text-index program will output data to a TMP directory while indexing. If your filesystem has low diskspace for /tmp you can set an alternative temporary directory using the environment variable TMPDIR=~/alt_tmp_dir/ jbrowse text-index.

How does the jbrowse text-index trix format work

The jbrowse text-index command creates text searching indexes using trix. The trix indexes are based on the format described by UCSC here https://genome.ucsc.edu/goldenPath/help/trix.html but we reimplemented the code the create these index formats in the JBrowse CLI so you do not have to install the UCSC tools.

The main idea is that you give trix

GENEID001  Wnt signalling
GENEID002 ey Pax6

Then this will generate a new file, the .ix file, sorted in alphabetical order

ey  GENE002
signalling GENE001
Pax6 GENE002
Wnt GENE001

Then a second file, the .ixx file, tells us at what byte offset certain lines in the file are e.g.

signa000000435

Note that JBrowse creates a specialized trix index also. Instead of creating a ix file with just the gene names, it also provides their name and location in an encoded format.

Developers

How can I start the JBrowse 2 app as a developer

We recommend that you have the following

Then you can follow steps from our README

It basically boils down to git cloning our repo, and running yarn start which creates a development server on port 3000

You can use PORT=8080 yarn start to manually specify a different port

Note that this is a development server that gets started up. To install jbrowse 2 in production on your webserver, see below

Do you have any tips for learning React and mobx-state-tree

Here is a short guide to React and mobx-state-tree that could help get you oriented

https://gist.github.com/cmdcolin/94d1cbc285e6319cc3af4b9a8556f03f

What technologies does JBrowse 2 use

We build on a lot of great open source technology, some main ones include

  • React
  • mobx-state-tree
  • web-workers
  • Typescript
  • Electron (for desktop specifically)

Should I configure gzip on my web server

Yes! JBrowse 2 may load ~5MB of JS resources (2.5MB for main thread bundle, 2.5MB for worker bundle). If you have gzip enabled, the amount of data the user has to download though is only 1.4MB. We have worked on making bundle size small with lazy loading and other methods but adding gzip will help your users.

It will depend on your particular server setup e.g. apache, nginx, cloudfront, etc. how this may be done, but it is recommended to look into this.