- •Contents
- •Notices
- •Trademarks
- •Preface
- •The team who wrote this book
- •Now you can become a published author, too!
- •Comments welcome
- •Stay connected to IBM Redbooks
- •Chapter 1. Introduction
- •1.1 The opportunity of the in-memory database
- •1.1.1 Disk databases cannot expand to memory
- •1.1.2 IBM solidDB IMDB is memory-friendly
- •1.1.3 Misconceptions
- •1.1.4 Throughput and response times
- •1.2 Database caching with in-memory databases
- •1.2.1 Databases are growing
- •1.2.2 Database caching off-loads the enterprise server
- •1.2.3 IBM solidDB Universal Cache
- •1.3 Applications, competition, and the marketplace
- •Chapter 2. IBM solidDB details
- •2.1 Introduction
- •2.2 Server architecture
- •2.2.1 Database access methods and network drivers
- •2.2.2 Server components
- •2.3 Data storage in solidDB
- •2.3.1 Main-memory engine
- •2.4 Table types
- •2.4.1 In-memory versus disk-based tables
- •2.4.2 Persistent versus non-persistent tables
- •2.4.3 Choosing between different table types
- •2.5 Transactionality
- •2.5.1 Concurrency control and locking
- •2.5.2 Isolation levels
- •2.5.3 Durability levels
- •2.6 solidDB SQL extensions
- •2.6.1 solidDB SQL standard compliance
- •2.6.2 Stored procedures
- •2.6.3 Triggers
- •2.6.4 Sequences
- •2.6.5 Events
- •2.6.6 Replication
- •2.7 Database administration
- •2.7.1 Configuration settings
- •2.7.2 ADMIN COMMAND
- •2.7.3 Data management tools
- •2.7.4 Database object hierarchy
- •Chapter 3. IBM solidDB Universal Cache details
- •3.1 Architecture
- •3.1.1 Architecture and key components
- •3.1.2 Principles of operation
- •3.2 Deployment models
- •3.3 Configuration alternatives
- •3.3.1 Typical configuration
- •3.3.2 Multiple cache nodes
- •3.3.3 SMA for collocation of data
- •3.3.4 solidDB HSB servers for high availability
- •3.4 Key aspects of cache setup
- •3.4.1 Deciding on the replication model
- •3.4.2 Defining what to replicate
- •3.4.3 Starting replication
- •3.5 Additional functionality for cache operations
- •3.5.1 SQL pass-through
- •3.5.2 Aging
- •3.5.3 Improving performance with parallelism
- •3.6 Increasing scale of applications
- •3.6.1 Scaling strategies
- •3.6.2 Examples of cache database applications
- •3.7 Enterprise infrastructure effects of the solidDB Universal Cache
- •3.7.1 Network latency and traffic
- •3.7.3 Database operation execution
- •Chapter 4. Deploying solidDB and Universal Cache
- •4.1 Change and consideration
- •4.2 How to develop applications that use solidDB
- •4.2.1 Application program structure
- •4.2.2 ODBC
- •4.2.3 JDBC
- •4.2.4 Stored procedures
- •4.2.5 Special considerations
- •4.3 New application development on solidDB UC
- •4.3.1 Awareness of separate database connections
- •4.3.2 Combining data from separate databases in a transaction
- •4.3.3 Combining data from different databases in a query
- •4.3.4 Transactionality with Universal Cache
- •4.3.5 Stored procedures in Universal Cache architectures
- •4.4 Integrate an existing application to work with solidDB UC
- •4.4.1 Programming interfaces used by the application
- •4.4.2 Handling two database connections instead of one
- •4.5 Data model design
- •4.5.1 Data model design principles
- •4.5.2 Running in-memory and disk-based tables inside solidDB
- •4.5.3 Data model design for solidDB UC configurations
- •4.6 Data migration
- •4.7 Administration
- •4.7.1 Regular administration operations
- •4.7.2 Information to collect
- •4.7.3 Procedures to plan in advance
- •4.7.4 Automation of administration by scripts
- •Chapter 5. IBM solidDB high availability
- •5.1 High availability (HA) in databases
- •5.2 IBM solidDB HotStandby
- •5.2.1 Architecture
- •5.2.2 State behavior of solidDB HSB
- •5.2.3 solidDB HSB replication and transaction logging
- •5.2.4 Uninterruptable system maintenance and rolling upgrades
- •5.3 HA management in solidDB HSB
- •5.3.1 HA control with a third-party HA framework
- •5.3.2 HA control with the watchdog sample
- •5.3.3 Using solidDB HA Controller (HAC)
- •5.3.4 Preventing Dual Primaries and Split-Brain scenarios
- •5.4 Use of solidDB HSB in applications
- •5.4.1 Location of applications in the system
- •5.4.2 Failover transparency
- •5.4.3 Load balancing
- •5.4.4 Linked applications versus client/server applications
- •5.5 Usage guidelines, use cases
- •5.5.1 Performance considerations
- •5.5.2 Behavior of reads and writes in a HA setup
- •5.5.3 Using asynchronous configurations with HA
- •5.5.4 Using default solidDB HA setup
- •5.5.5 The solidDB HA setup for best data safeness
- •5.5.6 Failover time considerations
- •5.5.7 Recovery time considerations
- •5.5.8 Example situation
- •5.5.9 Application failover
- •5.6 HA in Universal Cache
- •5.6.1 Universal Cache HA architecture
- •5.6.2 UC failure types and remedies
- •6.1 Performance
- •6.1.1 Tools available in the solidDB server
- •6.1.2 Tools available in InfoSphere CDC
- •6.1.3 Performance troubleshooting from the application perspective
- •6.2 Troubleshooting
- •Chapter 7. Putting solidDB and the Universal Cache to good use
- •7.1 solidDB and Universal Cache sweet spots
- •7.1.1 Workload characteristics
- •7.1.2 System topology characteristics
- •7.1.3 Sweet spot summary
- •7.2 Return on investment (ROI) considerations
- •7.2.1 solidDB Universal Cache stimulates business growth
- •7.2.2 solidDB server reduces cost of ownership
- •7.2.3 solidDB Universal Cache helps leverage enterprise DBMS
- •7.2.4 solidDB Universal Cache complements DB2 Connect
- •7.3 Application classes
- •7.3.1 WebSphere Application Server
- •7.3.2 WebLogic Application Server
- •7.3.3 JBoss Application Server
- •7.3.4 Hibernate
- •7.3.5 WebSphere Message Broker
- •7.4 Examining specific industries
- •7.4.1 Telecom (TATP)
- •7.4.2 Financial services
- •7.4.3 Banking Payments Framework
- •7.4.4 Securities Exchange Reference Architecture (SXRA)
- •7.4.5 Retail
- •7.4.6 Online travel industry
- •7.4.7 Media
- •Chapter 8. Conclusion
- •8.1 Where are you putting your data
- •8.2 Considerations
- •Glossary
- •Abbreviations and acronyms
- •Index
5.4.3 Load balancing
In addition to the transparent failover built-in functionality, the solidDB JDBC/ODBC drivers also contain support for load balancing of the query execution.
The basis for the load balancing is the fact that there are two (HotStandby) databases running at the same time, and the two databases are in sync regarding the content. Therefore, any read query will provide the same result regardless of whether it is executed in the Primary or the Secondary database.
When the load balancing is activated, the JDBC/ODBC driver uses two physical connections, one to each database, and allocates the query load to the workload connection. The workload connection is selected based on query type (such as
read or write), and the then-current load in the database servers.
Several main principles in the solidDB HotStandby load balancing implementation are as follows:
Read-only queries (at the read committed isolation level) can be executed in either database.
Read queries needing higher isolation level (repeatable read, select for update) are executed in the Primary database.
Write queries are executed in the Primary database.
Read queries after any write operation within same transaction are executed in the Primary database (to ensure that updated rows are visible for subsequent reads).
Internal read/write level consistency of the databases is ensured so that after a write transaction is committed, the secondary database is not used for
reading from the same connection until the secondary database is up-to-date for that write. This way eliminates the possibility that if the 1-safe or 2-safe received HotStandby replication protocol is used, the next read transaction would not see committed data from the previous write transaction.
The selection of the workload connection is automated by IBM solidDB, and the load balancing is automatic and transparent to the application.
As a result, especially read-centric applications can easily balance out the load between the two database servers, and use the full CPU capacity of both servers.
The load balancing is activated with ODBC driver by setting the PREFERRED_ACCESS connection attribute to value READ_MOSTLY; or with
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