Sequoia Transparent middleware solution offering clustering, load balancing and failover services for any database
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control balance database controller wrapper load balancer communication wrapper

Sequoia Description

Transparent middleware solution offering clustering, load balancing and failover services for any database Sequoia is the core technology providing database clustering capabilities. It is composed of a controller implementing the RAIDb (Redundant Array of Inexpensive Databases) technology.Sequoia controllers are replicated for HA and scalability purposes. Controllers use group communication to synchronize the cluster. Hedera is a group communication wrapper that can be plugged to work with multiple group communication implementations such as Appia, JGroups or Spread.Sequoia comes with a JDBC driver for Java application. Additional drivers for PHP, ODBC, MySQL native API, Perl, and C/C++ applications are also provided through the Carob project. with transparent fail over capabilities.NOTE: Sequoia is dual-licensed and distributed under the Apache License, Version 2.0 and the Gnu Public License (GPL), Version 2.0. Here are some key features of "Sequoia": · No modification of existing applications or databases. · Operational with any database providing a JDBC driver. · High availability provided by advanced RAIDb technology. · Transparent failover and recovery capabilities. · Performance scalability with unique load balancing and query result caching features. · Integrated JMX-based administration and monitoring. · 100% Java implementation allowing portability across platforms with a JRE 1.4 or greater. What's New in This Release: · - Clobs are not really implemented · - Sequoia may not store data records with semicolon · - Long idled persistent connections can see exceptions when sending a new request to MySQL · - Initialize command might fail with crashed recovery log · - backup with MS JDBC driver for MS SQL Server 2005 · - Raidb1 load balancer and WaitForCompletionPolicy=first does not work · - Recovery log stops processing and tries to enable database if there is an unparsable statement in the recovery log · - DatabaseSQLMetaData.createDatabaseSchema hides exceptions that could be thrown by call to metaData.getExportedKeys(null, null, null) · - Recovery log does not correctly invalidate prepared statements when idle connection is timed out · - Cannot restart an Embedded Sequoia Controller because the PingResponder thread is not shutdown. · - wait for all members to join @ joinGroup is to short for Appia · - Enable Backend sends 2 equal JMX Notifications · - WARN Distributed Set savepoint did not remove itself from the total order queue is shown when a controller has no backend. · - Controller floods log with messages when applications connect with an older driver · - Failover due to controller crash during a commit statement can issue the following warning "Transaction 4 was aborted by database" · - Adding a VDB to a controller with the 'force' flag set will result in a 'Unique Constraint Violation' SQLException if VDB is already the 'last man down'. · - Streaming Resultet containing database specific datatype columns may show 'Internal bug: tried to receive using the UNDEFINED deserializer' error · - Some read requests do not have a valid request id. This can lead to this error message : 'Request '0' failed (A query with id 0 has already been scheduled)' · - If 2 controllers are too asynchronous, then a backend may be disabled because of a request failing on one controller and not the other one · - Sequoia.dtd missing attribute definition for idleConnectionTimeout · - RAIDb1 callStoredProcedure and execWriteRequest methods enforce abort of transaction in case of concurrent abort, but do not log abort completion in the recovery log · - Error message when a transaction is aborted due to deadlock : Unable to retrieve connection for transaction · - Error when using CallableStatement with OUT and IN/OUT parameters: No value specified for parameter · - AbstractScheduler.abortRemainingActiveTransactions will stop aborting transactions at the first failing abort. · - Test connection statements are not properly closed · - Recovery Log consistency check fails using Derby as the database · - backup system throws exception because pending read request has not been processed · - PreparedStatement.GetMetaData leak memory · - Exception when executing getExportedKeys(null, null, null) : java.sql.SQLException: Table name can not be null · - alwaysGetGeneratedKeys should also work for replace statements · - StringIndexOutOfBoundsException when retrieving MySQL years as dates · - preparedStatementGetParameterMetaData not retried on second controller in case of no backend available · - Duplicate shutdown checkpoint names with non-distributed virtual databases · - Backend state not restored from recovery log with non-distributed virtual databases · - Call to metadata.getExportedKeys() generates NPE in SequoiaSchemaFactory · - Recovery Log : RemoveCheckpointEvent should invalidate the connection before being retried · - NPE in DatabaseBackend.terminateDeadlockDetectionThread · - Begin not logged in recovery log for non-distributed virtual databases · - with more than one firebird backend controller throws NPE · - NullPointerException when trying to transfer a dump · - Non-distributed RAIDb-1 demo is broken · - Transaction with multiple locks competing with a stored procedure have a wrong lock list · - Add port to Backuper dumpServer specification · - Handle recovery log database failure · - PATCH: Support for controller "safe shutdown" via Runtime.getRuntime().addShutdownHook() · - Idle connection timeout · - Provide an option to avoid full schema refresh each time a create table statement is done against the cluster · - SQL Console should not use query timeouts · - Provide a better logging while replaying the recovery log and finding a task marked as still "Executing" · - Applications with large numbers of SQL syntax errors fill up full_cluster.log with extraneous warnings and messages · - Macro replacement should not occur for select requests · - Upgrade to JGroups 2.4.2 · - Cross-schema updates should generate a hard error that stops the application · - Add RequestInterceptor feature to allow easy addition of logic to monitor and transform requests · - Implement PreparedStatement.getParameterMetaData() method · - Add JMX Notifications for joinMember() and failedMember() · - Extend Sequoia controller to handle differences in backend driver handling of setFetchSize() hints · - Add defaultFetchSize property to JDBC driver to make it easier to handle very large result sets in the controller · - Implement new console command to show the activity status of a vdb. · - Derby Backuper for Network Server running locally · - Patch for fixed JMX-RMIServer port

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