Main featues included in releases FTS 2.2 - 2.2.3

Changes from FTS version 2.1 to 2.2.3

SRM-gridftp split

Channel occupation is now calculated differently for url-copy channels.
FTS transfers in url-copy channels are divided in three phases: preparation, transfer and finalization.
During the preparation phase FTS contacts the two SRM endpoints to make sure that all the prerequisites for the transfer to be successful are met: the servers are reachable, the source file exists, the target directory exists and so on. During the finalization phase, FTS communicates to the servers that the transfer has completed successfully, the TURLs can be released and so on. It is only during the transfer phase that data transfer is actually taking place and bandwidth is used.

To illustrate the different scheduling mechanism, let's assume that some transfers are scheduled on a channel configured with 2 files, where the duration of the different phases for each transfer is summarized in the table bewlow.

TX ID Preparation phase Transfer phase Finalization phase
TX 1 10 30 10
TX 2 5 25 10
TX 3 15 25 10
TX 4 15 20 10
TX 5 10 10 10

With FTS versions up to 2.1, the limit on the number of files configured on a channel was meant as the maximum number of active transfers in any phase at any given time. tx_timeline_fts21.gif This scheduling mechanism is not very efficient. See, for example, that Transfer 3 start only when transfer 2 is completed: in the interval from 40 to 50 seconds there are 2 active transfers, but none of them is actually transferring data.

With FTS version 2.2, the number of files on a channel is meant as the maximum number of transfers in the transfer phase at any given time. tx_timeline_fts22.gif In this example, at the beginning, 4 transfers instead of 2 are started (this ratio is configurable, see INSERT LINK for details). Transfers 1 and 2, the first reaching the end of the preparation phase, switch immediately to the actual transfer phase, and as soon as they end their transfer phases other ones are started so that there are always 2 actual data transfer processes.

From FTS 2.2.3, you can choose between the old and new behavior. See the GUC_SRMGRIDFTPSPLIT Yaim variable in the FTS Configuration Reference page. By default, the new behavior is disabled!

Timeouts based on gridftp transfer markers

The timeout parameters based on gridftp transfer markers have been reviewed. Transfer markers indicate that the server is alive and give information about the transfer progress.

This graph shows a possible example of transfer progress as indicated by the received markers: tx_progress_timeouts.gif

The meaning of first transfer marker timeout has been slightly modified from version 2.1: it is now consiedered as the maximum amount of time, after the transfer starts, before receving the first non-zero transfer marker (previously it was the time before receiving the first marker): tx_progress_first_tx_mark_to.gif

The newly introduced no activity timeout is the maximum amount of time with markers showing no progress: tx_progress_no_activity_timeout.gif

As in previous versions, the transfer markers timeout indicates the maximum amount of time without receiving markers: tx_progress_tx_marks_timeout.gif

New transfer parameters

Handling WLCG requests for extra transfer parameters. For the "Addendum to the SRM v2.2 WLCG Usage Agreement" document check the CCRC'08 Wiki Page.

Copy pin lifetime: a copy pin lifetime can be specified with the --copy-pin-lifetime of the glite-transfer-submit command line tool.

For urlcopy channels, copy pin lifetime is set in two places:

  • in the storageSystemInfo array of key-value pairs of the srmPrepareToPut operation, in a key called CopyPinLifetime
  • in an additional srmBringOnline operation performed after the copy has succeeded (successful srmPutDone), in the desiredLifetime parameter.

For srmcopy channels, copy pin lifetime is set in two places:

  • in the targetStorageSystemInfo array of key-value pairs of the srmCopy operation, in a key called CopyPinLifetime
  • in an additional srmBringOnline operation performed after the copy has succeeded, in the desiredLifetime parameter.

The additional call to srmBringOnline is a workaround to deal with storage elements that will not provide a short term implementation of the ExtraInfo parameters handling, and will probably be removed in next versions.

Source space token in srmCopy operations: Now the source space token option is set for srmcopy channels as well, in the sourceStorageSystemInfo array of key-value pairs of the srmCopy operation, in a key called SourceSpaceToken. The source space token was already correctly handled in srmPrepareToGet operations for urlcopy channels.

Transfer type: it is now possible to specify ConnectionType=LAN in the TransferParameters field of the srmPrepareToGet / srmPrepareToPut operations. Use the --lan-connection flag of glite-transfer-submit. This should be useful for intra-site transfers involving dCAche storage elements.

Fail nearline files: fail the transfer if the source file location is nearline, without attempting an srmPrepareToGet operation. Specify it with the --fail-nearline flag of glite-transfer-submit.

Delegation race condition

Fix for bug #60095: FTS: Couldn't set the private key glite-data-transfer-fts v3.7.0-3 2010-01-18

Logging improvements

Logging to syslog according to Middleware Security Audit Logging Guidelines.

Logging IP addresses in SRM calls.

Updated CLI

Site Groups (formerly known as clouds)

The CLI now correctly handles all the channel configuration parameters that have been moved to the database.

Added site groups management tools: glite-transfer-group-list, glite-transfer-group-addmember and glite-transfer-group-removemember.

The glite-transfer-submit-placement and glite-transfer-discovery commands are now obsolete, and no longer distributed.

See the documentation for FTS 2.2 CLI for details.

Checksum support

A client can specify checksums and ask FTS to check it with the source and/or destination SE via srmLs or gridftp calls:

glite-transfer-submit --compare-checksums source-SURL destination-SURL ADLER32:12345678

See more at FtsChecksums.

Fixed bugs

For a list of fixed bugs, see patches

FTS version PATCH SLC4/32
2.2 SLC4 i386
2.2.1 SLC4 i386
2.2.2 SLC4 i386
2.2.3 SLC4 i386

For upcoming releases see the FTS patch status page!

Known Issues

See Fts223KnownIssues
Last edit: UnknownUser on 2010-05-11 - 18:38
Number of topics: 1

Maintainer: AkosFrohner


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