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               Introduction to the Standalone WWW Blast server

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Index

   * Introduction
   * What's new in this revision?
   * Installation of the Standalone WWW server
   * Description of files in the distribution
   * Configuration of BLAST databases
   * PSI/PHI Blast notes
   * Client/server versions for Entrez lookup and taxonomy reports
   * Blast 2 sequences
   * XML output
   * Out of Frame BLASTX
   * RPS Blast
   * Description of tags for main BLAST input page
   * Server configuration file and logfile
   * How to debug WWW Blast programs

Introduction

This standalone WWW BLAST server suite of programs was designed similar to
the regular NCBI BLAST server and such command-line NCBI BLAST programs like
"blastall", "blastpgp", "rpsblast" and "megablast". It incorporates most
features, which exist in NCBI BLAST programs and should be relatively easy
to use. This server does not support any request queuing and load balancing.
As soon as the user hits a "Search" button, BLAST starts immediately if
entered information is valid. So, this server is not intended to handle
large load, which may exist in public service. Such queueing and
loadbalancing however may be implemented using such products as Load Sharing
Facility - "LSF" from Platform Computing Corporation. Interface to "LSF" was
implemented in NCBI, however this was not included in this suite. Standalone
server assumes that users have their own BLAST or RPS-BLAST database(s),
that should be searched and want to have a simple WWW interface to such
search. It is STRONLY recommended that user has experience in installation
and running standalone NCBI BLAST programs.

After files are uncompressed, server is ready to be used immediately. Any
customizations to the program are welcomed and may be done by experienced
programmers using source code, which is also provided. Recompilation of the
server executables require that programmer has compiled NCBI toolkit
libraries. This toolkit can be downloaded from the NCBI FTP web site:
ftp://ftp.ncbi.nih.gov

What's new in this revision?

 December 2002         * All binaries recompiled with the newest toolkit
                         version 2.2.5.
 August 2002           * Recompiled all binaries to include recent bug
                         fixes.
 June 2002             * Removed limit on the total length of database
                         names.
                       * Removed xmlblast.cgi and other unneeded XML
                         related files.
                       * Recompiled all programs.
 January 2002          * Removed formatdb, makemat and copymat binaries
                         from the archive - those should be taken from the
                         NCBI BLAST executables archive
                       * Added tabular output format
                       * Added option to mask lower case in query
 May, 2 2001           * No major changes. All programs have been
                         recompiled and made synchronous to the latest NCBI
                         tookit release.
 November 3, 2000      * Blast 2 sequences was added
 October, 19 2000      * RPS Blast was added
                       * Out of Frame BLASTX (OOF) now available for
                         testing and suggestions.
 September, 28 2000    * Added possibility to limit search to results of
                         Entrez query (Regular client/server BLAST)
 September, 11 2000    * Added MEGABLAST search.
                       * Added possibility to have multiple FASTA query
                         input - batch searches with multiple graphical
                         overviews. (Regular BLAST)
 August, 22 2000       * Added new advanced statistics to PSI Blast and
                         ability to produce Smith-Waterman alignments
                       * Added support for XML output.
 May, 17 2000          * PSI and PHI Blast were added to this distribution
                       * Added support for client/server interface for
                         gi/accesion lookups using Entrez
                       * Added possibility to print Taxonomy reports
                       * Added option to print alternative alignment with
                         specific color schema
 March, 20 2000        * Initial revision

Installation of the Standalone WWW server

After downloading the file wwwblast.Your_platform.tar.gz to your computer,
place it into document directory of HTTPD server and uncompress it by

    gzip -d wwwblast.Your_platform.tar.gz
    tar -xvpf wwwblast.Your_platform.tar

Please note that parameter "p" in tar options is significant - it will
preserve file access options stored in the distribution. Temporary directory
for BLAST overview images (TmpGifs) should have 777 permission, and logfiles
(wwwblast.log and psiblast.log) should have 666.

After you have uncompressed the distribution file, "blast" directory will be
created. You can access sample BLAST HTML input forms using URLs:

   * http://your_hostname/blast/blast.html
   * http://your_hostname/blast/blast_cs.html
   * http://your_hostname/blast/psiblast.html
   * http://your_hostname/blast/psiblast_cs.html
   * http://your_hostname/blast/megablast.html
   * http://your_hostname/blast/megablast_cs.html
   * http://your_hostname/blast/wblast2.html
   * http://your_hostname/blast/wblast2_cs.html

This distribution comes with 2 BLAST databases: "test_aa_db" - sample
protein database and "test_na_db" - sample nucleotide database. These
databases are configured to be searchable immediately with compatible BLAST
programs.

Description of files in the distribution

   * Root directory (./blast):

Files with suffix "*_cs.*" are analogous to the files without such suffix,
with added capability to make client/server Entrez lookups for sequence gis
and accessions.

blast.cgi, blast_cs.cgi          - BLAST search start-up C-shell files

.nlmstmanrc                      - Configuration file for the graphical
                                 overview image (do not edit!)
blast.html, blast_cs.html        - sample BLAST search input HTML forms
megablast.html,
megablast_cs.html                - sample MEGABLAST search input HTML forms
rpsblast.html, rpsblast_cs.html  - sample RPS BLAST search input HTML forms

blast.rc                         - Default configuration file for the WWW
                                 BLAST server

psiblast.rc                      - Default configuration file for the
                                 PSI/PHI WWW BLAST server

psiblast.cgi, psiblast_cs.cgi    - PSI/PHI BLAST search start-up C-shell
                                 files

psiblast.html, psiblast_cs.html  - sample PSI/PHI BLAST search input HTML
                                 forms
psiblast.REAL, psiblast_cs.REAL  - Main PSI/PHI BLAST server executables

wblast2.html, wblast2_cs.html    - sample BLAST 2 sequences search input
                                 HTML forms
wblast2.REAL, wblast2_cs.REAL    - Main BLAST 2 sequences server executables

bl2bag.cgi                       - CGI used to create 2 sequences alignment
                                 image on the fly

blast_form.map                   - Auxiliary map file for the front BLAST
                                 image

nph-viewgif.cgi                  - CGI program used to view and delete
                                 overview images
readme.html                      - this documentation
wwwblast.log                     - default logfile
psiblast.log                     - default PSI/PHI Blast logfile

ncbi_blast.rc                    - sample file for full NCBI set of
                                 databases

   * ./data directory - matrices used in BLAST search
   * ./db directory. - Files of test BLAST and RPS-BLAST databases.
   * ./docs: - HTML pages used in sample BLAST search input pages
   * ./images - images used in the sample BLAST search input pages
   * ./Src - source directory for the WWW BLAST server.
   * ./Src/XML - source directory for creation of files related to the XML
     output.
        o blstxml.asn - ASN.1 definition for Blast XML
        o blstxml.dtd - corresponding DTD
   * ./TmpGifs - storage for temporary BLAST overview gif files

Configuration of BLAST databases

To set up databases for the standalone WWW BLAST server, it is necessary to
follow these steps:

  1. Put a file with concatenated FASTA entries in the "./db" directory
  2. Run "formatdb" program, available from the NCBI ftp site to format the
     database.
  3. Add name of the database into server configuration file
  4. Add name of the database into (PSI/PHI) WWW BLAST search form

PSI/PHI Blast notes

There is one significant feature of the PSI/PHI Blast server: FASTA files
from which the BLAST databases are formatted should have GI numbers in all
sequence ids. This is almost always true for FASTA files from the NCBI FTP
site. Local databases may not be used with this version of PSI/PHI Blast
unless they have ">gi|12345..." prefix in the definition line.

Databases for the PSI/PHI Blast should always be created with formatdb using
the "-o T" flag. Test database "test_aa_db" was created using this flag and
database "test_na_db" was created without this flag.

If this distribution is installed not in the "/blast" directory under HTTPD
documents root directory, than path to the distribution should be set by an
environment variable WWW_ROOT_PATH in the file psiblast.cgi or
psiblast_cs.cgi

Client/server version for Entrez lookup and taxonomy reports

Regular Blast, PSI/PHI Blast, MegaBlast and Blast 2 Sequences have
client/server versions for Entrez gi/accession lookups and printing Taxonomy
reports. Configuration of client/server interface from the user to NCBI
should be done the same way as for any other client/server program to NCBI.
If program "blastcl3" works without problems, this server should work OK as
well. If user has firewall - default configuration will definitely fail to
work properly and this case will require special configuration. If user has
problems with such configuration, one should write to info@ncbi.nlm.nih.gov
for further assistance.

XML output

Possibility to produce XML output was added to this server. XML definition
of BLAST output is tied to the simple ASN.1 specification designed for this
case. These definitions may be found in the directory ./Src/XML. Any
recommendations on improvements to this (possible) standard may be sent to
blast-help@ncbi.nlm.nih.gov XML may be printed by setting "Alignment view"
in blast.html or (blast_cs.html) page to "BLAST XML". Resulting page will
look empty - but if you open the page source (in Netscape - View -> Page
source) - you will see the complete XML document.

Blast 2 sequences

Blast 2 sequences program was initially written by Tatiana Tatusova and Tom
Madden and was presented in the article: Tatiana A. Tatusova, Thomas L.
Madden (1999), "Blast 2 sequences - a new tool for comparing protein and
nucleotide sequences", FEMS Microbiol Lett. 174:247-250. The standalone WWW
version of the program mirrors the NCBI Blast 2 Sequences web page.

RPS Blast

RPS Blast or "Reversed Position Specific BLAST" is a very fast alternative
to the program IMPALA. It has the same general objective - to compare a
sequence to a collection of conserved domains (aka motifs, profiles, HMMs).
RPS Blast has a completely different implementation that has increased the
speed of profiles search 10 to 100 times depending on search conditions in
comarison to IMPALA. RPS Blast has an option to perform a translated search
of DNA sequences against these conserved domains. Currently RPS Blast is one
of the tools chosen to annotate human genome at NCBI and is the basis for
the CDD Blast search page.

Databases for RPS blast are hardware dependent - for speed reasons. Hence
they are different for big/little endian platforms.

To build RPS database it is necessary to follow the procedure explained in
the file "README.rps", that comes with this distribution. There is a small
RPS database available for testing. This database is a part of a real NCBI
database used in CDD search page. Full NCBI database is available in
platform-independent form from FTP site.

Out of Frame BLASTX

The OOF version of the blastx program finds alignments between a nucleotide
sequence translated into 3 frames and protein sequences, in which query
sequence frames can be shifted within one alignment. The algorithm and
low-level alignment functions were written by Zheng Zhang, currently at
Paracel Inc., and incorporated into regular BLAST API by Sergei Shavirin.

XML and tabular output are not yet implemented for the OOF alignments.

Description of tags for the main BLAST input page

This standalone server has a tag convention analogous to the regular NCBI
BLAST server. Sample BLAST search forms may be changed to accommodate
particular needs of the user in the custom search. Here is the list of these
tags and their meaning. If some tag is missing from the search input page,
it will take a default value. Exceptions are tags PROGRAM, DATALIB and
SEQUENCE (or SEQFILE), that should always be set.

   * PROGRAM - name of the BLAST program. Supported values include programs:
     blastn, blastp, blastx, tblastx and tblastn
   * DATALIB - name of the database(s) to search. This implementation
     includes possibility to use multiple databases. To use multiple
     databases several "DATALIB" tags should be used on the page for example
     using checkboxes (look for example at Microbial Genomes Blast Databases
     BLAST at NCBI). Note, that all of these databases should be properly
     written in the server configuration file.
   * SEQUENCE and SEQFILE - these tags used to pass sequence. First SEQUENCE
     tag is used for the input sequence. If it is missing, the SEQFILE tag
     is used instead.
   * UNGAPPED_ALIGNMENT - default BLAST search is a gapped search; this tag,
     if set, will turn gapped alignment off.
   * MAT_PARAM used to set 3 parameters at the same time. Value for this tag
     should be in format " " where mat_name - string name of the matrix
     (BLOSUM62, etc), d1 - integer for cost to open gap and d2 - cost to
     extend gap (-G and -E parameters in blastall respectably)
   * GAP_OPEN - set value for cost to open gap - 0 or missing tag invoked
     default behavior
   * GAP_EXTEND - set value for cost to extend gap - 0 or missing tag
     invoked default behavior
   * X_DROPOFF - Dropoff (X) for blast extensions in bits (default if zero)
     (-y parameter in "blastpgp" program)
   * GENETIC_CODE - Query Genetic code to use (for blastx only)
   * THRESHOLD_2 - Threshold for extending hits in second pass in multipass
     model search
   * MATRIX - Matrix (default is BLOSUM62) (-M in blastall)
   * EXPECT - Expectation value (-e in blastall)
   * NUM_OF_BITS - Number of bits to trigger gapping (-N in blastpgp)
   * NCBI_GI - If formated database use SeqIds in the NCBI format this
     option will turn printing of gis together with accessions.
   * FILTER - Multiple instances of values of this tag are concatenated and
     passed to the engine as "filter_string" ("L" for low complexity and "m"
     if filter should be set for lookup table only) - any letter will turn
     default filtering on - DUST for nucleotides and SEG for proteins (-F in
     blastall)
   * DESCRIPTIONS - Number of one-line descriptions in the output (-v in
     blastall)
   * ALIGNMENTS - Number of alignments to show (-b in blastall)
   * COLOR_SCHEMA - Color schema to use in printing of alternative
     alignment. This option is valid only for blastp and blastn programs. If
     set - it will override option set by "ALIGNMENT_VIEW"
   * TAX_BLAST - Print taxonomy reports. This option is valid only for
     client/server version of regular Blast
   * XML_OUTPUT - Print XML Blast output. All other alignment view options
     will be disabled
   * ENTREZ_QUERY - Limit search to results of Entrez query. Only for
     client/server version
   * RPSBLAST - This tag with turn "blastp" or "blastx" search into RPS
     Blast search for the rps blast database.
   * OOF_ALIGN -This flag if set to non-zero digit will turn on OOF
     alignment for "blastx" and will set frame shift penalty to this value.
   * OTHER_ADVANCED - this tag allows to input string analogous to the
     command line parameters of blastall. Setting parameter in
     OTHER_ADVANCED tag will override all other settings of this parameter.
     Supported options include:
        o -G gap open cost
        o -E gap extend cost
        o -q penalty for nucleotide mismatch
        o -r reward for nucleotide match
        o -e expect value
        o -W wordsize
        o -v Number of descriptions to print
        o -b Number of alignments to show
        o -K Number of best hits from a region to keep
        o -Y effective search space
   * ALIGNMENT_VIEW - will set type of alignment to show. Available options
     include:
        o 0 - Pairwise
        o 1 - query-anchored with identities
        o 2 - query-anchored without identities
        o 3 - flat query-anchored with identities
        o 4 - flat query-anchored without identities
        o 7 - BLAST XML (equivalent to setting the XML_OUTPUT tag)
        o 9 - Hit Table - to produce tabular output
   * OVERVIEW - used to turn on or off printing of alignment overview image
   * WWW_BLAST_TYPE - a special tag to distinguish different BLAST search
     types. See the description of a configuration file.

Server configuration file and logfile

Default configuration file is "blast.rc" and logfile "wwwblast.log". Setting
tag WWW_BLAST_TYPE to specific value may change these names. This is useful
if few different search input pages use the same CGI search engine, but
significantly different by content and priorities. A sample configuration
file comes with this distribution:

This file will set how many CPUs will be used in the BLAST search and what
databases may be used with what programs. Logfile currently stores only
limited information but also may be updated by programmers to store more
values in it. Please note, that usually HTTPD servers run by accounts that
do not have write access to disk, so the logfile permission should be set to
666.

How to debug WWW Blast programs

There is a way to debug these programs.

  1. Add line "setenv DEBUG_COMMAND_LINE TRUE" into the *.cgi file
     (uncomment it)
  2. Run search that results in the problem - this should create a file
     "/tmp/__web.in" in the "/tmp" directory.
  3. Set all necessary environment variables on the command line (BLASTDB at
     least) and run from command-line: "blast.REAL < /tmp/__web.in"

This should do your problematic search without WWW. If this resulted in
coredump - you may look into the core file with:

dbx blast.REAL core

and then use command "where" to print stack.

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BLAST Help Desk

Last modified: Fri Jan 11, 2002