Abstract: Duplicate bug report detection using machine learning algorithms and automated feedback incorporation is disclosed. For each set of bug reports, a user-classification of the set of bug reports as including duplicate bug reports or non-duplicate bug reports is identified. Also for each set of bug reports, correlation values corresponding to a respective feature, of a plurality of features, between bug reports in the set of bug reports is identified. Based on the user-classifications and the correlation values, a model is generated to identify any set of bug reports as including duplicate bug reports or non-duplicate bug reports. The model is applied to classify a particular bug report and a candidate bug report as duplicate bug reports or non-duplicate bug reports.

Abstract: A multi-node cluster is configured for credential management. A method commences by retrieving a super-user credential from a credential record stored in a location accessible to the cluster, then propagating the super-user credential to a set of nodes in the multi-node cluster. A credential creating processes is invoked on at least some of the set of nodes. Application-level credential access can be implemented in a multi-cluster environment by carrying-out an exchange that passes credentials between a first cluster and a second cluster over a secure channel. A protocol is observed whereby one or more applications running on the first cluster receive new credentials for accessing the second cluster from the credential serving process after the credential creating process creates the new credential.

Abstract: Techniques for universal cache management are described. In an example embodiment, a plurality of caches are allocated, in volatile memory of a computing device, to a plurality of data-processing instances, where each one of the plurality of caches is exclusively allocated to a separate one of the plurality of data-processing instances. A common cache is allocated in the volatile memory of the computing device, where the common cache is shared by the plurality of data-processing instances. Each instance of the plurality of data-processing instances is configured to: indentify a data block in the particular cache allocated to that instance, where the data block has not been changed since the data block was last persistently written to one or more storage devices; cause the data block to be stored in the common cache; and remove the data block from the particular cache. Data blocks in the common cache are maintained without being persistently written to the one or more storage devices.

Abstract: Techniques for universal cache management are described. In an example embodiment, a plurality of caches are allocated, in volatile memory of a computing device, to a plurality of data-processing instances, where each one of the plurality of caches is exclusively allocated to a separate one of the plurality of data-processing instances. A common cache is allocated in the volatile memory of the computing device, where the common cache is shared by the plurality of data-processing instances. Each instance of the plurality of data-processing instances is configured to: identify a data block in the particular cache allocated to that instance, where the data block has not been changed since the data block was last persistently written to one or more storage devices; cause the data block to be stored in the common cache; and remove the data block from the particular cache. Data blocks in the common cache are maintained without being persistently written to the one or more storage devices.

Abstract: A method, system, and computer program for high-availability database systems. The method commences by replicating (e.g., from a first server to a second server) a data structure having entries describing resource locks and client states. The replication can be performed to any number of servers. Upon detecting a failure of a connection between the first server and a client to which the first server is connected, the system establishes a new connection between the second server and the client by updating the replicated data structure to describe new connection between the second server and the client and updating the entries of the replicated data structure to reflect the new connection and the then current aspects of the resource locks and client states. The client can be a database instance, and the act of replicating can be accomplished using a broadcast channel. The servers can be organized in a computing cluster.

Abstract: A method, system, and computer program product for upgrade procedures in high-availability clustered systems. The method selects fail-over nodes during rolling patch installation and comprises steps for identifying a first node to upgrade, migrating services of the first node to a second node and shutting down the first node to perform its upgrade, then migrating the services back from the second node to the first node. When performing an upgrade of the other nodes of the cluster (e.g., nodes of the cluster other than the first node), rather than migrating the services of the node to be upgraded to another node that still needs to be upgraded, instead migrate the services of the node to be upgraded to a node that has already been upgraded. This reduces the brown-out time at least to the extent that this method incurs only one migration per node rather than two migrations per node.

Abstract: Embodiments enable a database management system (DBMS) to manage two levels of disk failure groups. These two levels of redundancy are achieved by grouping the disks of the disk group for the DBMS into two levels of failure groups (i.e., “data sites” each containing two or more “failure groups” of disks). This system of disk grouping allows a DBMS to potentially tolerate the loss of both an entire first site and part of a second site. Such a DBMS uses a multi-level voting system, based on both failure group-level votes and site-level votes, to identify the current version of administrative data structures (ADS) that store key administrative data. In addition to data sites that store database data, the DBMS includes a quorum site with a single quorum failure group that stores a copy of the ADS. The quorum site contributes a site-level vote during a multi-level voting event.

Abstract: A method, apparatus, and system for interposed file system driver is provided, which provides a logical file system on top of an existing base file system. One such interposed file system driver is a compression and deduplication layered driver (“COLD driver”). File system operations are intercepted from the operating system through the COLD driver, which is provided as an upper-level operating system driver that operates on top of an existing base file system. By processing file data through various modules, the existing base file system can be extended as a logical file system with compression, deduplication, indexing, and other functionality. The COLD driver can be implemented without requiring modifications to existing base file system structures or base file system drivers. Server deployments may thus leverage the additional file system functionality provided by the COLD driver without having to migrate to another file system.

Abstract: Techniques for universal cache management are described. In an example embodiment, a plurality of caches are allocated, in volatile memory of a computing device, to a plurality of data-processing instances, where each one of the plurality of caches is exclusively allocated to a separate one of the plurality of data-processing instances. A common cache is allocated in the volatile memory of the computing device, where the common cache is shared by the plurality of data-processing instances. Each instance of the plurality of data-processing instances is configured to: indentify a data block in the particular cache allocated to that instance, where the data block has not been changed since the data block was last persistently written to one or more storage devices; cause the data block to be stored in the common cache; and remove the data block from the particular cache. Data blocks in the common cache are maintained without being persistently written to the one or more storage devices.

Abstract: Duplicate bug report detection using machine learning algorithms and automated feedback incorporation is disclosed. For each set of bug reports, a user-classification of the set of bug reports as including duplicate bug reports or non-duplicate bug reports is identified. Also for each set of bug reports, correlation values corresponding to a respective feature, of a plurality of features, between bug reports in the set of bug reports is identified. Based on the user-classifications and the correlation values, a model is generated to identify any set of bug reports as including duplicate bug reports or non-duplicate bug reports. The model is applied to classify a particular bug report and a candidate bug report as duplicate bug reports or non-duplicate bug reports.

Abstract: Techniques for universal cache management are described. In an example embodiment, a plurality of caches are allocated, in volatile memory of a computing device, to a plurality of data-processing instances, where each one of the plurality of caches is exclusively allocated to a separate one of the plurality of data-processing instances. A common cache is allocated in the volatile memory of the computing device, where the common cache is shared by the plurality of data-processing instances. Each instance of the plurality of data-processing instances is configured to: identify a data block in the particular cache allocated to that instance, where the data block has not been changed since the data block was last persistently written to one or more storage devices; cause the data block to be stored in the common cache; and remove the data block from the particular cache. Data blocks in the common cache are maintained without being persistently written to the one or more storage devices.

Abstract: Systems, methods, and other embodiments associated with separating executables and working data of an application between separate images are described. In one embodiment, a method includes mounting an application image together with a working image to create an application directory for an application. The application image is read-only and includes at least an executable of the application and the working image includes working data modified by the application. The application directory provides files and paths of the files for the application together within a single unified directory while separating the executable in the application image from the working data in the working image. The method includes in response to receiving a write request to the application directory, arbitrating access to the application directory by controlling the processor to write data for the write request to the working image to maintain the working data separate from the executable of the application.

Abstract: Techniques are described herein for re-syncing a snapshot database with a base database. Data units of each database are associated with version numbers. When a data unit is modified, the data unit is associated with the current version number. When a snapshot database is re-synced with a base database, particular data units are copied from the base database to the snapshot database, based on the version number associated with the particular data units.

Abstract: Techniques are describe herein for associating storage management properties with a group of files of a database referred to herein as a “file group”. In this system, storage management properties are defined at the database-level. Thus, multiple databases can be stored across a single disk group, gaining the benefits of having multiple block access devices working in parallel, but each respective database may be associated with a respective file group in a one-to-one relationship, so that each database can have different storage management properties.

Abstract: A method, apparatus, and system for interposed file system driver is provided, which provides a logical file system on top of an existing base file system. One such interposed file system driver is a compression and deduplication layered driver (“COLD driver”). File system operations are intercepted from the operating system through the COLD driver, which is provided as an upper-level operating system driver that operates on top of an existing base file system. By processing file data through various modules, the existing base file system can be extended as a logical file system with compression, deduplication, indexing, and other functionality. The COLD driver can be implemented without requiring modifications to existing base file system structures or base file system drivers. Server deployments may thus leverage the additional file system functionality provided by the COLD driver without having to migrate to another file system.

Abstract: A method, apparatus, and system for interposed file system driver is provided, which provides a logical file system on top of an existing base file system. One such interposed file system driver is a compression and deduplication layered driver (“COLD driver”). File system operations are intercepted from the operating system through the COLD driver, which is provided as an upper-level operating system driver that operates on top of an existing base file system. By processing file data through various modules, the existing base file system can be extended as a logical file system with compression, deduplication, indexing, and other functionality. The COLD driver can be implemented without requiring modifications to existing base file system structures or base file system drivers. Server deployments may thus leverage the additional file system functionality provided by the COLD driver without having to migrate to another file system.

Abstract: A multi-node cluster is configured for credential management. A method commences by retrieving a super-user credential from a credential record stored in a location accessible to the cluster, then propagating the super-user credential to a set of nodes in the multi-node cluster. A credential creating processes is invoked on at least some of the set of nodes. Application-level credential access can be implemented in a multi-cluster environment by carrying-out an exchange that passes credentials between a first cluster and a second cluster over a secure channel. A protocol is observed whereby one or more applications running on the first cluster receive new credentials for accessing the second cluster from the credential serving process after the credential creating process creates the new credential.

Abstract: Systems, methods, and other embodiments associated with maintaining information about patches installed on a node are described. In one embodiment, a method includes, in response to installing a patch to a program, updating a list of installed patches in a computer by adding an identifier of the patch to the list of installed patches. The method also includes embedding the updated list of installed patches into compiled binary code of the program.

Abstract: A method, system, and computer program product for upgrade procedures in high-availability clustered systems. The method selects fail-over nodes during rolling patch installation and comprises steps for identifying a first node to upgrade, migrating services of the first node to a second node and shutting down the first node to perform its upgrade, then migrating the services back from the second node to the first node. When performing an upgrade of the other nodes of the cluster (e.g., nodes of the cluster other than the first node), rather than migrating the services of the node to be upgraded to another node that still needs to be upgraded, instead migrate the services of the node to be upgraded to a node that has already been upgraded. This reduces the brown-out time at least to the extent that this method incurs only one migration per node rather than two migrations per node.

Abstract: A method, system, and computer program for high-availability database systems. The method commences by replicating (e.g., from a first server to a second server) a data structure having entries describing resource locks and client states. The replication can be performed to any number of servers. Upon detecting a failure of a connection between the first server and a client to which the first server is connected, the system establishes a new connection between the second server and the client by updating the replicated data structure to describe new connection between the second server and the client and updating the entries of the replicated data structure to reflect the new connection and the then current aspects of the resource locks and client states. The client can be a database instance, and the act of replicating can be accomplished using a broadcast channel. The servers can be organized in a computing cluster.