man dblist (Administration système) - dblist

NAME

dblist - Database List Distributed Checksum Clearinghouse

SYNOPSIS

dblist [-vVHD] [-G on | off] [-h homedir] [-C 'type h1 h2 h3 h4']

[-I server-ID] [-A dbaddr] [-L pathlen] [-P pages] [-T timestamp]

[file1 file2 ...]

DESCRIPTION

Dblist

lists the contents of a DCC database as it does some consistency checking.

-v
lists more of the database. Additional information is produced with additional -v arguments.
-V
displays the version of the DCC database lister.
-H
turns off the listing of the hash table as well as the analysis of the hash table. Determining the worst case and average lengths of chains in the hash table can take a long time for a large database on a small computer.
-D
turns off the listing of the data or checksum records.
-G on
lists a greylist database.
-h homedir
overrides the default DCC home directory, which is often /var/dcc.
-C 'type h1 h2 h3 h4'
limits the listing to records containing that checksum or one of the other checksums specified with -C or server-IDs specified with -I. As many as 16 checksums can be specified.
-I server-ID
limits the listing to records with that server-ID or one of the other server-IDs specified with -I or checksums specified with -C . As many as 16 server-IDs can be specified.
-A dbaddr
excludes database records before dbaddr .
-L pathlen
excludes records with path lengths shorter than pathlen .
-P pages
ignores all but the last pages of the database.
-T timetamp
excludes records with other timestamps. As many as 16 timestamps can be specified.
file1 file2 ...
are names of databases to be listed. The default is dcc_db and its companion, dcc_db.hash in the DCC home directory.

By default, the sizes of the main file and the hash table as well as how much they contain and values related to the performance of the hash are displayed.

With a single -v , most of the mail database file and the contents of memory mapped server flooding positions in the flod.map file are listed. The listing starts with the serial number of the database file which is when old entries were last removed from it by dbclean() That is followed by similar lines showing the oldest timestamp of checksums not expired by dbclean and of mail that is not "spam."

The flooding positions from the flod.map file are record offsets or addresses in the main database file.

A typical record in the main database file looks like: 02/07/02 20:25:12.497032 5 auth 1601 2fe5b94 path: 103<-101<-1601 Body 6 e2d3f96a c65aea01 3fece361 edff9ecf 2f21364 772d2 Fuz1 many 6ff56fe8 ffc312d7 a5fe8f13 12a537ae 2f21364 200a9 Fuz2 many fac882b8 03eea34f bd792c40 2fe6fd54 2f21364 72816

That example was received by a DCC server with server-ID at about 8:25 GMT on the evening of February 7, 2000. The report was about a mail message set to addressees. The report was from a client that presented a client-ID and matching password that the server recognized or authenticated. The report was then sent or to the server with server-ID which in turn sent it to a server with server-ID That server sent it to the local DCC server. The record is at the address in the database. The record contains 3 checksums. The simple checksum of the body of the message was The total number of recipients of messages with this body checksum known in the database is which implies this checksum had been previously reported with a target count of 1. The previous report in the database of a message with this body checksum is at The hash table entry for this body checksum is at This report included two fuzzy checksums. Both have been previously reported as having been sent to targets.

An asterisk (*) before the name of the checksum would indicate that a later record in the database makes this checksum redundant. A report of addressees makes all preceding reports redundant.

The string after the server-ID marks older reports that have had uninteresting checksums removed. The string after the server-ID would indicate that this older report has been trimmed and compressed with older reports.

With two -v arguments, records added to the database by dbclean() from the server whitelist are also displayed.

Three -v arguments cause the hash table to be displayed. Three typical hash table entries look like: 19b8: 19ee 19b7 19b9: 19c0 0 90120 Fuz1 19ba: 0 0 1b72300 Fuz1

The entry in slot number is unused or free. Slot number is the start of a chain of collisions or entries with the same hash value of 0x19b9. The next slot in this chain is at The corresponding checksum is at in the database. The third slot at is also that of a checksum, but it is not part of a hash chain and its database record is at

FILES

/var/dcc
is the DCC home directory containing data and control files.
dcc_db grey_dcc_db
main file of checksums.
dcc_db.hash grey_dcc_db.hash
database hash table.
flod.map grey_flod.map
memory mapped flooding positions.

SEE ALSO

cdcc(8) ,dcc(8) ,dbclean(8) ,dccd(8) ,dccifd(8) ,dccm(8) ,dccproc(8) .

HISTORY

Implementation of was started at Rhyolite Software in 2000. This describes version 1.2.74.