Gravic, Inc.

Intel Corporation

Iti, Inc.

Rpx Corporation

Gravie, Inc.

Paul J Holenstein

Bruce D Holenstein

John R Hoffmann

Wilbur H Highleyman

Dylan R Holenstein

Gary E Strickler

Eugene P Jarema

Owen C Davison

Victor F Berutti

Jonathan M Ziegler

Tristan E Hoffmann

Keith B Evans

Joseph A Wynn

William A Grimm

Herbert William Knapp

Methods are provided for preventing constraint violations at a target database by a database replication system. The database replication system replicates database transactions from a change log of a source database to the target database. Each source database and each target database have one or more tables, and at least one of the target database tables has one or more constraints. The database replication system replicates database transactions from a change log for the source database to the target database. Each of the source database tables has an associated change log disk cache. For each database transaction, a database change is detected to the at least one of the source database tables that potentially causes a constraint violation at the target database as a result of one or more of the target database tables having one or more constraints. An application call, or a programmatic call by a database management system, is then made when the database change is detected to flush to a change log disk contents of the associated change log disk cache for the at least one of the source database tables which has a change log disk cache that may flush to the change log disk in a misordered manner compared to change log disk cache flushes from at least one other source database table. The application call, or the programmatic call by the database management system, prevents the potential constraint violation at the target database by the database replication system.

Methods for preventing constraint violations at a target database by a database replication system where an application call, or a programmatic call by a database management system, forces a flush of a change log

A method, apparatus, and computer program product are provided for combining output responses corresponding to a plurality of matching user requests in a transaction response combiner (TRC) that includes memory. Each output response includes response details. The TRC receives an output response for each of the user requests. Each output response is tagged with an identifier that corresponds with the respective user request. At least some of the tagged output responses are inserted into the memory. It is detected when an output response received at the TRC has one or more corresponding output responses in the memory by searching for output responses that have the same tag. Rules of a rules engine are applied to combine the output responses received at the TRC for each of the matching user requests into a final output response. The rules of the rules engine are applied to the corresponding output responses with the same tag, and to the response details for the output responses that share the same detected tag. The final output response is outputted by the TRC.

Method, apparatus and computer program product for combining output responses corresponding to a plurality of matching user requests in a system that validates transactions

An automated method is provided for comparing a first database table and a second database table with each other to produce a table of differences therebetween. The first database table and the second database table include one or more subsets of data that are intended to match each other. The first database table and the second database table each include multiple rows, each row having multiple columns. A first set of indicia is generated comprising indicia for a subset of the columns of each of the multiple rows of a subset of the first database table, and a second set of indicia is generated comprising indicia for a subset of the columns of each of the multiple rows of a subset of the second database table. The second set of indicia are generated without regard to an original order of the columns in the second database. The indicia in the first set of indicia are compared with the indicia in the second set of indicia on a row-by-row basis, wherein the comparing occurs without regard to an original order of the rows in the second database table. Any indicia in the first set of indicia that are not present in the second set of indicia are identified, thereby identifying a first set of mismatched indicia. Likewise, any indicia in the second set of indicia that are not present in the first set of indicia are identified, thereby identifying a second set of mismatched indicia. The table of differences is populated with the identified indicia. The second database table may be repaired by using at least one of the first set of mismatched indicia and the second set of mismatched indicia.

Method for comparing rows of subsets of two database tables without regard to an original order of rows and columns in either database table

Commit latency is reduced for pending transactions. The transactions are replicated from a source database to a target database by a replication engine. The pending transaction is incomplete in either the source or the target database. A transaction pattern table is provided that includes a plurality of records, each record being defined by a transaction pattern identifier. Each record includes a transaction pattern and a metric of occurrence of the transaction pattern. A comparison is made of the series of one or more transaction steps or operations of a pending transaction to the transaction patterns in the transaction pattern table, and a subset of transaction patterns in the transaction pattern table are identified that are potential candidates for matching the pending transaction. The pending transaction is categorized using the metric of occurrence of the transaction pattern for each transaction pattern in the subset of transaction patterns. The categorizing predicts when all of the series of one or more transaction steps or operations which have completed in the source database have been replicated. The metric of occurrence of the transaction pattern for each record of the transaction pattern table is (i) a count that is continuously updated based on completed transactions that match the transaction pattern, or (ii) a prepopulated probability of occurrence of the transaction pattern, or (iii) derived from historical data of the transaction pattern. The pending transaction is then processed using the categorization of the pending transaction.

Apparatus, method, and computer program product for reducing commit latency of pending transactions

A method and system are provided for comparing a first database table and a second database table with each other to produce a table of differences therebetween. The first database table and the second database table include one or more subsets of data that are intended to match each other, and the first database table and the second database table each include multiple rows. Indicia is generated for each of the multiple rows of a subset of the first database table, and each of the multiple rows of a subset of the second database table. The generated indicia for each of the multiple rows of the subset of the first database table are compared with the generated indicia for the subset of each of the multiple rows of the subset of the second database table, on a row-by-row basis, wherein the comparing occurs without regard to an original order of the rows in either the first database table or the second database table. Any generated indicia for each of the multiple rows of the subset of the first database table that are not present in the generated indicia for each of the multiple rows of the subset of the second database table are identified as a first set of mismatched indicia. Any generated indicia for each of the multiple rows of the subset of the second database table that are not present in the generated indicia for each of the multiple rows of subset of the first database table are identified as a second set of mismatched indicia. The table of differences is populated with the generated indicia. The second database table may be repaired by using at least one of the first set of mismatched indicia and the second set of mismatched indicia.

Method and apparatus for comparing rows of subsets of two database tables without regard to an original order of rows in either database table

A method and apparatus are provided for processing a document and validating data integrity and reliability of document processing results. The document includes one or more data collection areas which are located in and are part of the document and which are configured to receive input by a person who enters information in the one or more data collection areas, and a unique identifier which is located in and is part of the document. In operation, a document is received at the document distributor which distributes an electronic representation of the document to each of two or more document processing systems, each of which has an associated database. Processing of the document is initiated in each of the two or more document processing systems by reading the unique identifier of the document, interpreting any inputted information in the one or more data collection areas, and updating the associated database for each of the two or more document processing systems with document processing results including the read unique identifier of the document, and any interpreted inputted information. A hash value is computed in each of the two or more document processing systems, for each of the document processing results. A validation engine matches the computed hash values. The validation engine validates data integrity and reliability of the document processing results when the computed hash values match. The processing of the document in the database of each of the two or more document processing systems is then finalized when the data integrity and reliability of the document processing results has been validated. In one embodiment, the document is an election ballot.

Method and system for processing a document and validating data integrity and reliability of document processing results

An automated method and apparatus are provided for comparing a first database and a second database that are intended to be kept in synchronization with each other. Applications process changes that are posted to the first database and the second database. Changes made to the first database are applied to the second database, and vice-versa. Changes made to the first database resulting from changes posted to the first database are collected into a first change log. Changes made to the second database resulting from changes posted to the second database are collected into a second change log. Representations of the changes that correspond to the same respective changes in the change logs are compared with each other. Corrective action is performed when the comparison indicates that the corresponding representations of the changes in the first change log and the second change log do not match.

Method and apparatus for continuously comparing two databases which are actively being kept synchronized

A method is provided for performing transaction processing in a system. The system includes a plurality of nodes. Each node in the system includes a processor, an application executing in the processor, and a local queue. Each node executes multiple user transactions. Each transaction includes a BEGIN step, and one or more data manipulation language (DML) or data definition language (DDL) operations. In operation, two of the nodes are selected to receive the same user request to process the transaction. The processor at each of the two nodes executes in the application the same user request to process the transaction. Local indicia is created at each of the two nodes from the outcome of the transaction steps and operations of the transaction and is then exchanged with the other of the two nodes. The processor at each of the two nodes puts on their respective local queues the local indicia created at the same node as the processor, and the local indicia received from the other of the two nodes. One of the local queues of one of the nodes detects whether the two local indicia match each other. A COMMIT is executed in the processor at the one node for the transaction when a match occurs. As a result of this process, multiple user requests are processed on the two nodes even when they occur out of order on the two nodes.

Validation architecture servicing multiple user requests by queuing and then matching out of order indicia

Output responses corresponding to a plurality of matching user requests are combined in a transaction response combiner (TRC). Each output response includes response details. The TRC receives an output response for each of the user requests. Each output response is tagged with an identifier that corresponds with the respective user request. It is detected when an output response received at the TRC has one or more corresponding output responses by searching in the memory for output responses that have the same tag. Rules of a rules engine are applied to combine the output responses received at the TRC for each of the matching user requests into a final output response. The rules of the rules engine are applied to the corresponding output responses with the same tag, and to the response details for the output response that shares the same detected tag. The final output response is outputted by the TRC.

Method, apparatus, and article of manufacture for combining output responses corresponding to a plurality of matching user requests

A method is provided for validating transactions in a system that includes indeterministic ordering of change log events by using deterministic indicia. The system includes a plurality of nodes. Each node in the system includes an instance of a database used by an application, and a change log associated with the instance of the database used by the application. Each node executes transactions. Each transaction has a plurality of subsets including one or more data manipulation language (DML) or data definition language (DDL) operations. Results of the DML or DDL operations are stored in the change log as change log events, wherein the order of the change log events stored in the change log on one node is in a different order than the order of change log events stored in the change log of at least one of the other nodes. For each subset of a transaction executing at each node, deterministic subunits of the change log events are defined. Indicia are then computed for each subunit of the change log events. The subunits are ordered by the computed indicia. Deterministic indicia are then computed for the subset of the transaction from the ordered subunits. The subset of the transaction is then validated with at least one of the other nodes using the deterministic indicia. The validation indicates either a match or a mismatch of the deterministic indicia computed at the plurality of nodes. This process is then repeated for one or more remaining subsets of the plurality of subsets of the transaction.

Method for validating subsets of transactions in a system that includes indeterministic ordering of change log events by using deterministic indicia of the transaction subsets

An apparatus is provided for resolving an unintended transaction rollback in a system that includes an audited database, a non-audited application, and a facility for converting non-audited applications to use audited database transactions, wherein the unintended transaction rollback is the result of a failure of the facility to convert the unintended transaction rollback to a commit operation, The non-audited application is operated with the facility creating database transactions against the audited database. The database transactions include one or more transaction steps or operations. The created database transactions are monitored to detect transaction rollbacks. A determination is made when a detected transaction rollback for a database transaction is an unintended transaction rollback. The one or more transaction steps or operations of the database transaction that included the unintended transaction rollback are recovered in the audited database. The recovering resolves the unintended transaction rollback. The monitoring, determining, and recovering are performed by an Automatic Transaction Facility (ATF) recovery engine.

Apparatus for resolving automatic transaction facility (ATF) failures

Hung transactions which are completed within a transaction processing system are resolved. The transactions are replicated from a source database to a target database by a replication engine. The hung transaction is incomplete in either the source or the target database. A transaction pattern table is provided that includes a plurality of records, each record being defined by a transaction pattern identifier. Each record includes a transaction pattern and a metric of occurrence of the transaction pattern. A comparison is made of the series of one or more transaction steps or operations of a hung transaction to the transaction patterns in the transaction pattern table, and a subset of transaction patterns in the transaction pattern table are identified that are potential candidates for matching the hung transaction. The hung transaction is categorized using the metric of occurrence of the transaction pattern for each transaction pattern in the subset of transaction patterns. The categorizing predicts when all of the series of one or more transaction steps or operations which have completed in the source database have been replicated. The metric of occurrence of the transaction pattern for each record of the transaction pattern table is (i) a count that is continuously updated based on completed transactions that match the transaction pattern, or (ii) a prepopulated probability of occurrence of the transaction pattern, or (iii) derived from historical data of the transaction pattern. The hung transaction is then processed using the categorization of the hung transaction.

Apparatus, method, and computer program product for resolving hung transactions

A method and system are provided for comparing a first database table and a second database table with each other to produce a table of differences therebetween. The first database table and the second database table include one or more subsets of data that are intended to match each other, and the first database table and the second database table each include multiple rows. Indicia is generated for each of the multiple rows of the first database table, and each of the multiple rows of the second database table. The generated indicia for each of the multiple rows of the first database table are compared with the generated indicia for each of the multiple rows of the second database table, wherein the comparing occurs without regard to an order of the rows in either the first database table or the second database table. Any generated indicia for each of the multiple rows of the first database table that are not present in the generated indicia for each of the multiple rows of the second database table are identified as a first set of mismatched indicia. Any generated indicia for each of the multiple rows of the second database table that are not present in the generated indicia for each of the multiple rows of the first database table are identified as a second set of mismatched indicia. The table of differences is populated with the generated indicia.

Method and apparatus for comparing two database tables without regard to an original order of rows in either database table

A method and apparatus are provided for avoiding target database constraint violations in a database replication system. The database replication system includes a source database and a target database, wherein target database transactions automatically abort due to constraint violations. Each database has one or more tables and at least one of the target database tables has one or more constraints. The database replication system replicates source database transactions. For each target database transaction corresponding to a replicated source database transaction, changes made at the source database are replicated to the target database. When it is detected that a replicated change causes a constraint violation as a result of one or more of the target database tables having one or more constraints, the applying of the database change to the target database of the database change is deferred and the database change is posted to an electronic list. Replicated changes that do not cause a constraint violation are immediately applied to the target database. This process is repeated for all of the changes within the replicated source database transaction. The database changes on the electronic list are iterated through by applying the database changes on the electronic list that no longer cause a constraint violation to the target database and removing the applied database changes from the electronic list, and by deferring again the applying of the database changes on the electronic list that still cause a constraint violation and maintaining the deferred database changes on the electronic list. A commit is performed for the target database transaction corresponding to the replicated source database transaction when a commit operation is detected in the replicated source database transaction, and when no database changes remain on the electronic list for the replicated source database transaction. The deferring process avoids the target database transactions automatically aborting due to constraint violations.

Method and apparatus for resolving target database constraint violations in a database replication system where target database transactions are automatically aborted due to constraints violations

An automated method and apparatus are provided for comparing a source database and a target database that are intended to be kept in synchronization with each other. An application processes database changes that are posted to the source database and replicated to the target database. The source database and the target database are made up of blocks of data. Blocks of data from the source database having database changes are collected. These blocks of data are replicated to the target database. Blocks of data from the target database that correspond to the blocks of data from the source database having database changes are read. Representations of the blocks of data from the source database having database changes are compared to representations of blocks of data from the target database that correspond to the blocks of data from the source database having database changes. A corrective action is performed when the comparison indicates that the representations of the blocks of data from the source database having database changes do not match the representations of blocks of data from the target database that correspond to the blocks of data from the source database having database changes. A similar process is performed using 'before images' of blocks of data from the source database having database changes and then comparing representations of these “before images” to representations of “current images” of blocks of data from the target database that correspond to the before images of blocks of data from the source database having database changes.

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Downingtown, PA, United States of America

Paul J Holenstein