Glossary
Archive ID¶
TODO
Archive Metadata¶
Optional json-formatted data that can be passed to give various . Implementation is under works.
ATRESYS¶
Automated Tape REpacking SYStem, see tools documentation.
CASTOR¶
The predecessor to CTA.
Catalogue¶
CTA Catalogue is a Relational DB which contains the tape file namespace, permanent system data configuration and its state changes.
Ceph¶
TODO
CTA Frontend¶
The component of the CTA system which acknowledges user requests being received and mainly interacts with the Disk Instance.
CTA Instance [Name]¶
TODO
ctaproductionfrontend¶
Default frontend in production instanceName for user queues.
ctaproductionrepackfrontend¶
Alias that points to the relevant frontend for repack queues
ctacephproductionrepackfrontend¶
CTA frontend with cephProductionRepack schedulerDB backend
ctapostgresproductionrepackfrontend¶
CTA frontend with postgresProductionRepack backend
cta-admin¶
TODO
cta-taped¶
TODO
Data Acquisition System¶
TODO
Disk Instance¶
A deployment of a disk buffer for CTA system which could be a dCache of an EOS storage system. In the documentation we use it also as a different term for “EOSCTA instance”, the ‘small EOS’ instance used to archive/retrieve files from tape. A Disk Instance can have one or multiple VOs assigned to it. At CERN we have created a dedicated Disk Instance for each of the large LHC experiments (eosctaatlas, ...) , in addition to instances shared by the small/medium sized experiments (eosctapublic, eosctapublicdisk), based on their archival needs.
EOS¶
TODO
EOSCTA¶
TODO
EOS Instance¶
TODO
EOS Space¶
TODO
File Archival¶
TODO
File Lifecycle¶
TODO
File Preparing¶
TODO
File Retrieval¶
TODO
File Storage Server¶
TODO
File Staging¶
TODO
File Transfer System¶
TODO
Fluentd¶
TODO
gRPC¶
TODO
Kerberos¶
TODO
Kerberos keytab¶
TODO
Liquibase¶
Liquibase is an open-source database-independent library for tracking, managing and applying database schema changes.
Media Type¶
TODO
Mount Rule¶
Mount Rule is a group of Disk Instance name, user/group requester name, mount policy name and and activity regex expression which together point to a specific Mount Policy.
mhVTL¶
TODO
Mount Policy¶
Named set of parameters (e.g. priority, minimum request age) assigned to each transfer type. It is one of the main input parameters for the Scheduler which determines the eligibility of a particular transfer queue to trigger a Tape Mount.
ObjectStore¶
ObjectStore is an object database, a specialized type of NoSQL database designed to handle data created by applications that use object-oriented programming techniques, avoiding the object–relational mapping overhead required when using object-oriented data with a relational database.
OStoreDB¶
OStoreDB is the CTA API to the ObjectStore serving as the SchedulerDB (i.e. used as a metadata backend for scheduling operations).
RelationalDB¶
RelationalDB is the CTA API to a relational database (PostgreSQL) serving as the SchedulerDB (i.e. used as a metadata backend for scheduling operations).
Puppet¶
TODO
Protobuf¶
TODO
readtp¶
TODO
Repack¶
The act of copying/moving data from one magnetic tape to another, for purposes such as moving data away from potentially defect media, for data replication across multiple cartridges, or for moving to a more recent media generation.
Remote Media Changer Daemon¶
TODO
RPM¶
TODO
rsyslog¶
TODO
Rundeck¶
TODO
Scheduler¶
A component of the CTA system which is responsible for deciding when a tape shall be mounted into a tape drive.
SchedulerDB¶
Metadata backend for the Scheduler. This can be an Object Store, a File system or a Relational Database. Its purpose is to hold all transient transfer metadata and their changes.
SSS Key¶
TODO
Storage Class¶
TODO
Tape Buffer¶
TODO
Tape Cartridge¶
TODO
Tape Daemon¶
Process runing on a Tape Server which takes care of scheduling the mount and spawning several threads taking care of the process of writing or reading from a tape, maintenance and reporting of CTA workflows, etc..
Tape Mount¶
Assignment of a Tape Drive to a Tape for a set of existing transfers to be executed.
Tape Drive¶
The physical device used for reading or writing to tape. We can have several tape drives being operated by one tape server.
Logical Library¶
Logical library is used to partition resources (tape drives and cartridges) of a physical tape library. Normally, it is a combination of a physical library name and a tape drive type. Disabling a logical library will prevent new mounts on the tape drives defined in that particular logical library (running transfers will continue). Example - Name: IBMLIB1-LTO9, Disabled: false, Physical library: IBMLIB1. This parameter links the Tape Drives with the set of tapes which the tape drives can operate on, i.e. not all drives can read and write to all tapes.
Tape Library¶
TODO
Tape Lifecycle¶
TODO
Tape Pool¶
Logical collection of tapes used to manage (a) file ownership; (b) where the file should be physically stored.
Tape Server¶
A server which runs the necessary processes to perform efficient operations on a tape library, i.e. decides to mount tapes into drives, and participates in read/write processes as well as in all necessary maintanence operations.
Tape Slot¶
TODO
Tape Supply¶
TODO
Tape Supply Pool¶
TODO
Tier-0 Site¶
TODO
Tier-1 Site¶
TODO
Tier-2 Site¶
TODO
transfer request¶
One transfer request may contain more than one transfer job. This is true especially for archiving where multiple copies may have been requested to be stored on tape.
Virtual Organization¶
A grouping of users working with the same data/experiment. As an example, for CTA at CERN each LHC experiment (ATLAS, …), as well as small and medium sized experiments (AMS, NA62, …), is assigned to a dedicated VO with the same name. VOs are used to enforce quotas, such as an experiment’s number of dedicated drives, as well as to gather usage statistics and summaries for each experiments.
XRootD¶
TODO
XRootD SSI¶
TODO