Database Framework

Nikolay Malitsky

EPICS Collaboration MeetingOct. 7–14, 2010, BNL, NY, USA

Outline

Big picture Priorities DB-3 DB-4 and DB-3

Typical three-tier control system environment

EPICS +=Your

Server

EPICS 4 = EPICS 3 + Middle Layer

Priorities:

1. Preserve the Gold Part of EPICS 3:collection of drivers contributed by the EPICS community

2. Add the support of structured data

3. More …

EPICS 4 = EPICS 3 + Middle Layer

PV Data API

DB Framework

DB-3 Adapter

DB-3

Structured Records

DDS Dynamic Data API

PV Access Server

…

DDS AMQP ZeroMQ CAS 3

Different Types of Servers ….

…

DDS Extensible Dynamic Topic Types The (excellent) industrial specification of the (excellent) PVData idea.

• RFP: June 27, 2008• Revised Submission: February 22, 2010• Adopted Beta 1: May 21, 2010• Deadline for comments: November 29, 2010• FTF (Finalization Task Force) Recommendation and Report : April 4, 2011

Addressed Topics:

Timeline:

• Type System: C language, sparse types, type versioning and evolution• Type Representation: XML, TypeObject (binary), …• Data Representation: CDR, …, Google’s Protocol Buffers, …• Language Binding: a few interfaces, DynamicType and DynamicData.

Everything looks great, but: DynamicData Interface is heavy

Good news: • Our proposal with 30 methods presented at the OMG technical meeting, Sept. 20-23, 2010, Boston• Preliminary agreement to build the open-source code co-owned by EPICS, RTI, and PrismTech.

DB-3

dbRecordType

name (e.g. “ai”)

dbCommon rset

dset

aiRecordaiRSET

aidset

*extent

devAiSoft

…

…

dbBase

*

Record-specific interfaces and associations (defined in the external file)

Device-specific implementations

2. Direct interface

1. Generic interface for the server requests Algorithms: record and

device supportsData

Containers

1. Separation of data containers and device supports2. Collection of fine-grain records vs a coarse-grain device model.

DB-3 and DB-4

dbBase

dbRecordType

name (e.g. “ai”)

dbCommon rset

dset

aiRecordaiRSET

aidset

*

*extent

db::PVBase

db::PVStructure*

extent

rec3::PVRecordManager

rec3::AiRecordManager

DB-3

db::PVRecordManager

*db::PVRecord

rec3::AiRecord

create

DB-4

rec3::PVStructure

rec3::AiStructure

rec3::PVSupport

db::PVSupport

rec3::AiSupport

process

rec3::AiRecord

Automatically generated from the db files