Abstract: Some embodiments relate to assigning individual log messages to clusters. An initial cluster assignment may be performed by applying a hash function to one or more non-variable components of the message to generate an initial cluster identifier. Subsequently, clustering may be further refined (e.g., by determining whether to merge clusters based on similarity values). An interface can present a representative message of each cluster and indicate which portions of the message correspond to a variable component. Particular inputs detected at the input corresponding to one of these components can cause other values for the component to be presented. For a given cluster, timestamps of assigned messages can be used to generate a time series, which can facilitate grouping of clusters (with similar or complementary shapes) and/or triggering alerts (with a condition corresponding to a temporal aspect).

Abstract: Some embodiments relate to assigning individual log messages to clusters. An initial cluster assignment may be performed by applying a hash function to one or more non-variable components of the message to generate an initial cluster identifier. Subsequently, clustering may be further refined (e.g., by determining whether to merge clusters based on similarity values). An interface can present a representative message of each cluster and indicate which portions of the message correspond to a variable component. Particular inputs detected at the input corresponding to one of these components can cause other values for the component to be presented. For a given cluster, timestamps of assigned messages can be used to generate a time series, which can facilitate grouping of clusters (with similar or complementary shapes) and/or triggering alerts (with a condition corresponding to a temporal aspect).

Abstract: Some embodiments relate to assigning individual log messages to clusters. An initial cluster assignment may be performed by applying a hash function to one or more non-variable components of the message to generate an initial cluster identifier. Subsequently, clustering may be further refined (e.g., by determining whether to merge clusters based on similarity values). An interface can present a representative message of each cluster and indicate which portions of the message correspond to a variable component. Particular inputs detected at the input corresponding to one of these components can cause other values for the component to be presented. For a given cluster, timestamps of assigned messages can be used to generate a time series, which can facilitate grouping of clusters (with similar or complementary shapes) and/or triggering alerts (with a condition corresponding to a temporal aspect).

Abstract: Disclosed is a system, method, and computer program product for analyzing sets of data in an efficient manner, such that analytics can be effectively performed over that data. Classification operations can be performed to generate groups of similar log records. This permits classification of the log records in a cohesive and informative manner.

Abstract: Techniques for leveraging frequent patterns identified in a captured workload are provided. In one approach, multiple frequent patterns detected in a captured workload may be ordered by frequency to determine, for example, which patterns should be targeted for optimization. In another approach, a model of a captured workload is created, where the model comprises nodes that represent templates (which in turn correspond to requests) and edges that represent transitions between templates. The model is used to create an artificial workload, such as a workload that is twice as large as the originally-captured workload. The model may also be edited before creating the artificial workload. In another approach, workload models are compared to identify errors, regressions, or security issues. In another approach, an artificial workload is created for an application that is not yet deployed and then executed to determine whether the artificial workload or the originally-captured workload executed faster.

Abstract: An application workload capture and replay system with a transactionally consistent application workload replay feature is provided. More particularly, the feature includes capture-phase components for capturing and recording a real application workload submitted to a production web application system and includes replay-phase components for replaying the captured application workload against a test web application system in a transactionally consistent manner. The feature provides guarantees about the order of database transactions that are caused when the workload is replayed such that there is a consistency between the replay-phase order of the database transactions and the order of those transactions that occurred when the workload was captured. These consistency guarantees facilitate a faithful reproduction of database changes observed in the production web application system in the test web application system using a captured real application workload.

Abstract: A database system providing transactionally consistent replay of application workloads. In a database system, a method providing transactionally consistent replay of application workloads comprises the steps of: during a replay phase in which a plurality of application requests that were previously submitted to an application server system during a capture phase are being replayed, receiving, at a database server, a database request to execute a database command against a database. The database request specifies an application request identifier that identifies a particular application request of the plurality of application requests. The particular application request caused the database command to be executed previously during the capture phase. In response to receiving the database request, determining, based on the application request identifier in the database request, whether to delay execution of the database command at least until a particular replay-phase database transaction has been committed.

Abstract: A database system providing transactionally consistent replay of application workloads. In a database system, a method providing transactionally consistent replay of application workloads comprises the steps of: during a replay phase in which a plurality of application requests that were previously submitted to an application server system during a capture phase are being replayed, receiving, at a database server, a database request to execute a database command against a database. The database request specifies an application request identifier that identifies a particular application request of the plurality of application requests. The particular application request caused the database command to be executed previously during the capture phase. In response to receiving the database request, determining, based on the application request identifier in the database request, whether to delay execution of the database command at least until a particular replay-phase database transaction has been committed.

Abstract: An application workload capture and replay system with a transactionally consistent application workload replay feature is provided. More particularly, the feature includes capture-phase components for capturing and recording a real application workload submitted to a production web application system and includes replay-phase components for replaying the captured application workload against a test web application system in a transactionally consistent manner. The feature provides guarantees about the order of database transactions that are caused when the workload is replayed such that there is a consistency between the replay-phase order of the database transactions and the order of those transactions that occurred when the workload was captured. These consistency guarantees facilitate a faithful reproduction of database changes observed in the production web application system in the test web application system using a captured real application workload.

Abstract: Disclosed herein are an intelligent system and method for monitoring a generator reactive power limit using machine model parameters. The intelligent system and method for monitoring a generator reactive power limit using machine model parameters can calculate a maximum reactive power limit corresponding to over-excitation and a generator terminal voltage corresponding to under-excitation, estimate a correct field current even when system variable are changed, and monitor the generator reactive power limit by using machine model parameters and a one-machine infinite bus, to thereby supply a maximum or minimum reactive power to a power system within an allowable generator reactive power limit and prevent a generator trip caused by the reactive power limit and a power failure over a wide area.

Abstract: Disclosed herein are an intelligent system and method for monitoring a generator reactive power limit using machine model parameters. The intelligent system and method for monitoring a generator reactive power limit using machine model parameters can calculate a maximum reactive power limit corresponding to over-excitation and a generator terminal voltage corresponding to under-excitation, estimate a correct field current even when system variable are changed, and monitor the generator reactive power limit by using machine model parameters and a one-machine infinite bus, to thereby supply a maximum or minimum reactive power to a power system within an allowable generator reactive power limit and prevent a generator trip caused by the reactive power limit and a power failure over a wide area.

Abstract: A system and method are provided to calculate a real time voltage stability risk index in a power system. The method includes calculating an RMS voltage by using bus voltage measured and calculating an N moving average voltage for the RMS voltages. A percentage diversity between the bus voltage measured and the N moving average voltages is calculated. A voltage stability in that risk index is calculated by dividing the area constructed by the percent diversity by the number of sections. The voltage stability risk index is transferred from a real time phasor measurement device to an upper voltage stability monitoring system. The transferred voltage stability risk indexes are acquired and sequenced and the sequence voltage stability risk indexes are output.