Release Notes for NorduGrid ARC 6.8
October 8, 2020
We are pleased to announce the release of ARC 6.8.0.
This release comes with two important changes that affect the update, namely changes in the accounting system, and a dependency on xrootd5. Both will need manual steps when updating to ARC 6.8.0, the latter only if your CE has the nordugrid-plugins-xrootd package installed.
Accounting changes
The largest change in this release is the removal of the pre 6.4.0 accounting system. Since the accounting subsystem changes in 6.4.0 where we went from files to database, the old system has lived alongside the new. From 6.8.0 the legacy code is all removed. For more details of the consequences, and especially changes in arc.conf, please see the complete description of changes.
If you want to read more about the accounting changes, please consult the overview document. And, finally, you can consult description of the new system.
Please be aware that you will need to make changes in your arc.conf for ARC to start with 6.8.0.
Options and blocks that are no longer supported in arc.conf
- In the [arex/jura] block:
- urdelivery_keepfailed (in [arex/jura] block)
- In the [arex/jura/sgas:targetname] block:
- legacy_fallback
- In the [arex/jura/apel:targetname] block:
- use_ssl
- benchmark_type
- benchmark_value
- benchmark_description
- legacy_fallback
- [arex/jura/archiving] block (the whole block is deprecated)
- archivedir
- logfile
- archivettl
Important note on xrootd version for sites using the nordugrid-arc-plugins-xrootd package
For sites who install the nordugrid-arc-plugins-xrootd package note that ARC 6.8.0 is built with xrootd 5. On the date of the release xrootd 5 has not yet reached EPEL-stable, which means that to install(update) ARC 6.8.0 on RHEL-systems, you must enable the epel-testing repo: yum install(update) "nordugrid-arc*" --enablerepo=epel-testing or alternatively install xrootd 5 before updating ARC.
Highlights in this release
- Removal of the pre 6.4.1 accounting sub-system.
- Up until now the central datastaging.log file on the ARC-CE had a mix-up of the DTR-id's. This is now fixed in Bugzilla 3874.
- A benchmark option has been added to the lrms block to mitigate problems with missing benchmarks in the accounting, see details in the complete description of changes.
- APEL summary query speed up - issues with overloading frontend when updating from pre 6.4.1 to post 6.4.1 accounting system should now not occur. (Bugzilla 3893).
The following Bugzilla tickets have been adressed or solved
- 3959 Problem using delegated credentials in Ubuntu 20.04
- 3957 arcconfig-parser crash when $VAR variables are not defined
- 3956 Checksum is not correctly passed to xrootd libraries
- 3953 Cancelling a job in Preparing (pending) has no effect
- 3952 EMI-ES reports cancelled jobs as FAILED
- 3951 cleanup controldir
- 3950 log_failure_msg used in /usr/share/arc/arc-acix-scanner-start without being defined
- 3949 option to sbatch
- 3948 GRID_GLOBAL_JOBID is not full job id in EMI-ES
- 3946 Running arcctl commands as normal user silently fails
- 3942 Failed listing directory on GridFTP server
- 3940 startTime has no effect in EMIES/ADL
- 3927 arcproxy use legacy VOMS API and fails with IAM
- 3921 Benchmark information missing in accounting db when HTCondor backend used in "shared_filesystem = no" mode
- 3893 Accounting internal changes introduced in 6.4.1 causing overload on the frontend after update
- 3874 DTR id in datastaging logs
- 3838 Ensure space trimming in block names all over the code
Documentation
The ARC 6 documentation can be found at this location.
If you miss something or have questions, please contact us!
Installing ARC 6
We recommend to install ARC release using the Nordugrid repository.
- Start with the basics
- Get production ready
Note that if you instead install from EPEL for RHEL7 compatible systems, the ARC 6 packages can be found as nordugrid-arc6-* and not nordugrid-arc-*. This was needed in order to supply both ARC 5 already available for RHEL7 and the new ARC 6.
We provide binary builds for all supported versions of:
- Debian (i386 and amd64)
- Fedora (i386 and x86_64) - from Fedora 26 - no i386 support
- CentOS EL6 (i386 and x86_64) and EL7/EL8 (x86_64) - from EL7 no i386 support
- Ubuntu: (i386 and amd64, both LTS and interim releases) - from Ubuntu 20.04 no i386 support
In addition we build nightly packages for older platforms.
Future Support of ARC 5-series
As of June 2020 no more security updates are provided to ARC 5. Also since the release of ARC 6 in June 2019, no more development on the ARC 5 code base has been provided.
Production Sites already running ARC 5 will still get operational site support in form of deployment and configuration troubleshooting help via GGUS until end June 2021. However, we may recommend upgrading to ARC 6 depending on the issues the site is facing.
ARC5 is available in EPEL7 and will stay there. EPEL8 will only contain ARC 6. To install ARC 6 from EPEL7 the package-names are of type: nordugrid-arc6-*
Getting in touch
If you need help with the configuration file or have any other questions related to ARC 6, please contact us via
- Email: (Subscribe)
- Skype channel dedicated to ARC 6 support
Known issues
- In Centos8 the openldap server is not installable because slapd is not available in the RHEL8 release (Bugzilla 3944). As a consequence, the LDAP-based server-side information system interface of the ARC-CE will not be available either. If interaction with the ARC-CE relies on LDAP-based information schemas (glue1.3 or nordugrid schema), then we recommend that you stay with Centos7 for the time being.
- Related to the new accounting system introduded in release 6.4.0:
- Accounting records created by ARC 6.4.0 are affected by a bug causing missing benchmark values: Bug 3921, Comment 3 Recommendations are to update to a newer version of ARC. The bug report gives instructions on how to manually fix the wrong benchmark values.
Previous releases
Details of previous releases can be found at the ARC Releases page