Upload
gouse5815
View
228
Download
0
Embed Size (px)
Citation preview
8/9/2019 Distirbuted DataBase Architecture
1/23
Distributed DBMS Page 4. 1 1998 M. Tamer zsu & Patrick Valduriez
OutlineI IntroductionI Background Distributed DBMS Architecture Datalogical Architecture
Implementation Alternatives Component Architecture
Distributed DBMS Architecture Distributed Database Design Semantic Data Control Distributed Query Processing Distributed Transaction Management Parallel Database Systems Distributed Object DBMS Database Interoperability Current Issues
8/9/2019 Distirbuted DataBase Architecture
2/23
Distributed DBMS Page 4. 2 1998 M. Tamer zsu & Patrick Valduriez
I Defines the structure of the system components identified
functions of each component defined
interrelationships and interactions between componentsdefined
Architecture
8/9/2019 Distirbuted DataBase Architecture
3/23
Distributed DBMS Page 4. 3 1998 M. Tamer zsu & Patrick Valduriez
ANSI/SPARC Architecture
ExternalSchema
ConceptualSchema
InternalSchema
Internal view
Users
Externalview
Conceptualview
Externalview
Externalview
8/9/2019 Distirbuted DataBase Architecture
4/23
Distributed DBMS Page 4. 4 1998 M. Tamer zsu & Patrick Valduriez
Reference Model A conceptual framework whose purpose is to divide standardization
work into manageable pieces and to show at a general level how thesepieces are related to one another.
Approaches Component-based
N Components of the system are defined together with the
interrelationships between components.N Good for design and implementation of the system. Function-based
N Classes of users are identified together with the functionality thatthe system will provide for each class.
N The objectives of the system are clearly identified. But how do youachieve these objectives? Data-based
N Identify the different types of describing data and specify thefunctional units that will realize and/or use data according to these
views.
Standardization
8/9/2019 Distirbuted DataBase Architecture
5/23
Distributed DBMS Page 4. 5 1998 M. Tamer zsu & Patrick Valduriez
RELATION EMP [KEY = {ENO}
ATTRIBUTES = {ENO : CHARACTER (9)ENAME : CHARACTER (15)TITLE : CHARACTER (10)
}]RELATION PAY [
KEY = {TITLE}
ATTRIBUTES = {TITLE : CHARACTER (10)SAL : NUMERIC (6)
}]
Conceptual Schema Definition
8/9/2019 Distirbuted DataBase Architecture
6/23
Distributed DBMS Page 4. 6 1998 M. Tamer zsu & Patrick Valduriez
RELATION PROJ [KEY = {PNO}
ATTRIBUTES = {PNO : CHARACTER (7)PNAME : CHARACTER (20)BUDGET : NUMERIC (7)
}]RELATION ASG [
KEY = {ENO,PNO} ATTRIBUTES = {
ENO : CHARACTER (9)PNO : CHARACTER (7)RESP : CHARACTER (10)DUR : NUMERIC (3)
}]
Conceptual Schema Definition
8/9/2019 Distirbuted DataBase Architecture
7/23
Distributed DBMS Page 4. 7 1998 M. Tamer zsu & Patrick Valduriez
RELATION EMP [KEY = {ENO}
ATTRIBUTES = {ENO : CHARACTER (9)ENAME : CHARACTER (15)TITLE : CHARACTER (10)
}]
=========================================INTERNAL_REL EMPL [
INDEX ON E# CALL EMINXFIELD = {
HEADER : BYTE (1)E# : BYTE (9)ENAME : BYTE (15)TIT : BYTE (10)
}]
Internal Schema Definition
8/9/2019 Distirbuted DataBase Architecture
8/23
Distributed DBMS Page 4. 8 1998 M. Tamer zsu & Patrick Valduriez
Create a BUDGET view from the PROJ relation
CREATE VIEW BUDGET(PNAME, BUD) AS SELECTPNAME, BUDGET
FROM PROJ
External View Definition Example 1
8/9/2019 Distirbuted DataBase Architecture
9/23
8/9/2019 Distirbuted DataBase Architecture
10/23
Distributed DBMS Page 4. 10 1998 M. Tamer zsu & Patrick Valduriez
DBMS Implementation Alternatives
Distribution
Heterogeneity
Autonomy
Client/server
Peer-to-peer Distributed DBMS
Federated DBMS
Distributedmulti-DBMS
Multi-DBMS
8/9/2019 Distirbuted DataBase Architecture
11/23
Distributed DBMS Page 4. 11 1998 M. Tamer zsu & Patrick Valduriez
Dimensions of the ProblemI Distribution
Whether the components of the system are located on the samemachine or not
I Heterogeneity Various levels (hardware, communications, operating system) DBMS important one
N data model, query language,transaction management
algorithmsI Autonomy
Not well understood and most troublesome Various versions
N Design autonomy : Ability of a component DBMS to decide onissues related to its own design.
N Communication autonomy : Ability of a component DBMS todecide whether and how to communicate with other DBMSs.
N Execution autonomy : Ability of a component DBMS to executelocal operations in any manner it wants to.
8/9/2019 Distirbuted DataBase Architecture
12/23
8/9/2019 Distirbuted DataBase Architecture
13/23
Distributed DBMS Page 4. 13 1998 M. Tamer zsu & Patrick Valduriez
Datalogical Multi-DBMS
Architecture
...
GCS
GES 1
LCS 2 LCS n
LIS 2 LIS n
LES 11 LES 1 n LES n 1 LES nm
GES 2GES
n
LIS 1
LCS 1
8/9/2019 Distirbuted DataBase Architecture
14/23
Distributed DBMS Page 4. 14 1998 M. Tamer zsu & Patrick Valduriez
Timesharing Access to a CentralDatabase
Communications
DBMS Services
Network
Terminals or PC terminal emulators
Batchrequests Response
No datastorage
Hostrunning allsoftware
Application Software
Database
8/9/2019 Distirbuted DataBase Architecture
15/23
Distributed DBMS Page 4. 15 1998 M. Tamer zsu & Patrick Valduriez
Multiple Clients/Single Server
Communications
ClientServices
Applications
Communications
DBMS Services
LANHigh-levelrequests
Filtereddata only
Communications
ClientServices
Applications
Communications
ClientServices
Applications
Database
8/9/2019 Distirbuted DataBase Architecture
16/23
Distributed DBMS Page 4. 16 1998 M. Tamer zsu & Patrick Valduriez
Task DistributionApplication
Communications Manager
Communications Manager
Lock Manager
Storage Manager
Page & Cache Manager
Query Optimizer
QLInterface
ProgrammaticInterface
SQLquery
resulttable
Database
8/9/2019 Distirbuted DataBase Architecture
17/23
Distributed DBMS Page 4. 17 1998 M. Tamer zsu & Patrick Valduriez
Advantages of Client-Server Architectures
I More efficient division of laborI Horizontal and vertical scaling of resourcesI Better price/performance on client machinesI Ability to use familiar tools on client machinesI Client access to remote data (via standards)I Full DBMS functionality provided to client
workstationsI Overall better system price/performance
8/9/2019 Distirbuted DataBase Architecture
18/23
Distributed DBMS Page 4. 18 1998 M. Tamer zsu & Patrick Valduriez
Problems With Multiple-Client/Single Server
I Server forms bottleneckI Server forms single point of failureI Database scaling difficult
8/9/2019 Distirbuted DataBase Architecture
19/23
Distributed DBMS Page 4. 19 1998 M. Tamer zsu & Patrick Valduriez
Multiple Clients/Multiple Servers
Communications
ClientServices
Applications
LAN
I directoryI cachingI query decompositionI commit protocols
Communications
DBMS Services
Database
Communications
DBMS Services
Database
8/9/2019 Distirbuted DataBase Architecture
20/23
Distributed DBMS Page 4. 20 1998 M. Tamer zsu & Patrick Valduriez
Server-to-Server
Communications
DBMS Services
LAN
Communications
DBMS Services
I SQL interfaceI programmatic
interfaceI other application
supportenvironments
Communications
ClientServices
Applications
Database Database
8/9/2019 Distirbuted DataBase Architecture
21/23
Distributed DBMS Page 4. 21 1998 M. Tamer zsu & Patrick Valduriez
Peer-to-PeerComponent Architecture
Database
DATA PROCESSORUSER PROCESSOR
USER
Userrequests
System
responses
ExternalSchema
U s e r
I n t e r
f a c e
H a n
d l e r
GlobalConceptual
Schema
S e m a n
t i c
D a t a
C o n
t r o l l e r
G l o b a
l
E x e c u t
i o n
M o n
i t o r
SystemLog
L o c a
l R e c o v e r y
M a n a g e r
LocalInternalSchema
R u n
t i m
e
S u p p o r t
P r o c e s s o r
L o c a l
Q u
e r y
P r o c e s s o r
LocalConceptual
Schema
G l o b a
l Q u e r y
O p
t i m i z e r
GD/D
8/9/2019 Distirbuted DataBase Architecture
22/23
Distributed DBMS Page 4. 22 1998 M. Tamer zsu & Patrick Valduriez
Components of a Multi-DBMSGlobalRequestsResponses
D
BMS
UserInterface
QueryProcessorQuery
Optimizer
TransactionManager
Scheduler
RecoveryManager
Runtime Sup.Processor
USER
GTP GQP
GQOGS GRM
GUI
LocalRequests
Component Interface Processor(CIP)
D
BMS
UserInterface
QueryProcessorQuery
Optimizer
TransactionManager
Scheduler
RecoveryManager
Runtime Sup.Processor
LocalRequests
Component Interface Processor(CIP)
8/9/2019 Distirbuted DataBase Architecture
23/23
Distributed DBMS Page 4. 23 1998 M. Tamer zsu & Patrick Valduriez
Directory IssuesType
Location
Replication
Global & central& non-replicated
Local & central& non-replicated (?)
Global & distributed& non-replicated (?)
Local & distributed& non-replicated
Global & central& replicated (?)
Global & distributed& replicated
Local & distributed& replicated
Local & central
& replicated (?)