Biowulf High Performance Computing at the NIH
Rockhopper on Biowulf

From the Rockhopper manual:

Rockhopper is a comprehensive and user-friendly system for computational analysis of bacterial RNA-seq data. As input, Rockhopper takes RNA sequencing reads output by high-throughput sequencing technology (FASTQ, QSEQ, FASTA, SAM, or BAM files).

Rockhopper has a graphical interface which is described in the Rockhopper manual. For the cluster, the most relevant mode of usage is the command line interface.


  • B. Tjaden. De novo assembly of bacterial transcriptomes from RNA-seq data. Genome Biology 16:1 (2015) PubMed |  PMC |  Journal
Important Notes

Interactive job
Interactive jobs should be used for debugging, graphics, or applications that cannot be run as batch jobs.

Allocate an interactive session and run the program. If using the GUI, make sure that you have a graphical connection to biowulf (NX or X11 forwarding though ssh). Sample session:

[user@biowulf]$ sinteractive --mem=5g --cpus-per-task=4 --gres=lscratch:20
salloc.exe: Pending job allocation 46116226
salloc.exe: job 46116226 queued and waiting for resources
salloc.exe: job 46116226 has been allocated resources
salloc.exe: Granted job allocation 46116226
salloc.exe: Waiting for resource configuration
salloc.exe: Nodes cn3144 are ready for job

[user@cn3144]$ module load rockhopper

[user@cn3144]$ # start up the GUI. Need to know the http proxy host for this.
[user@cn3144]$ # Note that the proxy may change from session to session
[user@cn3144]$ echo $http_proxy
[user@cn3144]$ java -Dhttp.proxyHost=dtn03-e0 -Dhttp.proxyPort=3128 -jar $ROCKHOPPER_JAR

For more details on using the GUI, please see the Rockhopper manual. Now let's use the command line interface to do a reference based analysis of a small Mycoplasma genitalium data set:

[user@cn3144]$ cd /lscratch/$SLURM_JOB_ID
[user@cn3144]$ cp -r ${ROCKHOPPER_TEST_DATA:-none}/* .
[user@cn3144]$ tree
|-- [user    16M]  Example_Condition1.fastq
|-- [user    16M]  Example_Condition2.fastq
`-- [user   4.0K]  Mycoplasma_genitalium_G37
    |-- [user   575K]  NC_000908.fna
    |-- [user     46]  NC_000908.fna.fai
    |-- [user    10K]  NC_000908.genome
    |-- [user    59K]  NC_000908.gff
    |-- [user    37K]  NC_000908.ptt
    `-- [user   2.3K]  NC_000908.rnt

[user@cn3144]$ mkdir tmp
[user@cn3144]$ java -Xmx4000m$PWD/tmp -cp $ROCKHOPPER_JAR Rockhopper \
    -g $PWD/Mycoplasma_genitalium_G37 \
    -L cond1,cond2 \
    -o $PWD/results \
    Example_Condition1.fastq Example_Condition1.fastq

Aligning sequencing reads from file:    Example_Condition1.fastq
Total reads:                    137473
Successfully aligned reads:     125676  91%     (Mycoplasma genitalium G37 chromosome)
        Aligning (sense) to protein-coding genes:       96%
        Aligning (antisense) to protein-coding genes:   0%
        Aligning (sense) to ribosomal RNAs:     0%
        Aligning (antisense) to ribosomal RNAs: 0%
        Aligning (sense) to transfer RNAs:      1%

[user@cn3144]$ tree results
|-- [user   4.0K]  genomeBrowserFiles
|   |-- [user   1.4M]  Example_Condition1_NC_000908_v1_m15_aT_d500_l33_fr_cF.minus.wig
|   |-- [user   1.5M]
|   |-- [user   1.1M]  NC_000908_diffExpressedGenes.wig
|   |-- [user   1.1M]  NC_000908_ncRNAs.wig
|   |-- [user   1.3M]  NC_000908_operons.wig
|   `-- [user   1.1M]  NC_000908_UTRs.wig
|-- [user   4.0K]  intermediary
|   `-- [user   186K]  Example_Condition1_NC_000908_v1_m15_aT_d500_l33_fr_cF.gz
|-- [user   4.4K]  NC_000908_operons.txt
|-- [user    37K]  NC_000908_transcripts.txt
`-- [user   2.0K]  summary.txt

[user@cn3144]$ cp -r results /data/$USER

[user@cn3144]$ exit
salloc.exe: Relinquishing job allocation 46116226

Batch job
Most jobs should be run as batch jobs.

Create a batch input file (e.g., which uses the input file ''. For example:


module load rockhopper/2.0.3
cd /lscratch/$SLURM_JOB_ID
mkdir tmp

cp -r ${ROCKHOPPER_TEST_DATA:-none}/* .
java -Xmx4000m$PWD/tmp -cp $ROCKHOPPER_JAR Rockhopper \
    -g $PWD/Mycoplasma_genitalium_G37 \
    -L cond1,cond2 \
    -o $PWD/results \
    Example_Condition1.fastq Example_Condition1.fastq
cp -r results $wd

Submit this job using the Slurm sbatch command.

sbatch --cpus-per-task=4 --mem=5g