Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, a leader is selected from among candidate computing clusters. To make this selection, an activity monitor predicts or monitors the workload of one or more clients. Different activities of the workload are given corresponding weights. The delay in performing requested activities, modified by these weights is found, and the candidate leader with the lowest weighted delay is selected as the leader.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, a leader is selected from among candidate computing clusters. To make this selection, an activity monitor predicts or monitors the workload of one or more clients. Different activities of the workload are given corresponding weights. The delay in performing requested activities, modified by these weights is found, and the candidate leader with the lowest weighted delay is selected as the leader.

Abstract: Methods and systems for monitoring performance in a distributed storage system described. One example method includes identifying requests sent by clients to the distributed storage system, each request including request parameter values for request parameters; generating probe requests based on the identified requests, the probe requests including probe request parameter values for probe request parameter values, representing a statistical sample of the request parameters included in the identified requests; sending the generated probe requests to the distributed storage system over a network, wherein the distributed storage system is configured to perform preparations for servicing each probe request in response to receiving the probe request; receiving responses to the probe requests from the distributed storage system; and outputting at least one performance metric value measuring a current performance state of the distributed storage system based on the received responses.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, a leader is selected from among candidate computing clusters. To make this selection, an activity monitor predicts or monitors the workload of one or more clients. Different activities of the workload are given corresponding weights. The delay in performing requested activities, modified by these weights is found, and the candidate leader with the lowest weighted delay is selected as the leader.

Abstract: Methods and systems for monitoring performance in a distributed storage system described. One example method includes identifying requests sent by clients to the distributed storage system, each request including request parameter values for request parameters; generating probe requests based on the identified requests, the probe requests including probe request parameter values for probe request parameter values, representing a statistical sample of the request parameters included in the identified requests; sending the generated probe requests to the distributed storage system over a network, wherein the distributed storage system is configured to perform preparations for servicing each probe request in response to receiving the probe request; receiving responses to the probe requests from the distributed storage system, and outputting at least one performance metric value measuring a current performance state of the distributed storage system based on the received responses.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, a leader is selected from among candidate computing dusters. To make this selection, an activity monitor predicts or monitors the workload of one or more clients. Different activities of the workload are given corresponding weights. The delay in performing requested activities, modified by these weights is found, and the candidate leader with the lowest weighted delay is selected as the leader.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, a leader is selected from among candidate computing dusters. To make this selection, an activity monitor predicts or monitors the workload of one or more clients. Different activities of the workload are given corresponding weights. The delay in performing requested activities, modified by these weights is found, and the candidate leader with the lowest weighted delay is selected as the leader.

Abstract: Methods and systems for monitoring performance in a distributed storage system described. One example method includes identifying requests sent by clients to the distributed storage system, each request including request parameter values for request parameters; generating probe requests based on the identified requests, the probe requests including probe request parameter values for probe request parameter values, representing a statistical sample of the request parameters included in the identified requests; sending the generated probe requests to the distributed storage system over a network, wherein the distributed storage system is configured to perform preparations for servicing each probe request in response to receiving the probe request; receiving responses to the probe requests from the distributed storage system, and outputting at least one performance metric value measuring a current performance state of the distributed storage system based on the received responses.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, a leader is selected from among candidate computing clusters. To make this selection, an activity monitor predicts or monitors the workload of one or more clients. Different activities of the workload are given corresponding weights. The delay in performing requested activities, modified by these weights is found, and the candidate leader with the lowest weighted delay is selected as the leader.

Abstract: Methods and systems for monitoring performance in a distributed storage system described. One example method includes identifying requests sent by clients to the distributed storage system, each request including request parameter values for request parameters; generating probe requests based on the identified requests, the probe requests including probe request parameter values for probe request parameter values, representing a statistical sample of the request parameters included in the identified requests; sending the generated probe requests to the distributed storage system over a network, wherein the distributed storage system is configured to perform preparations for servicing each probe request in response to receiving the probe request; receiving responses to the probe requests from the distributed storage system; and outputting at least one performance metric value measuring a current performance state of the distributed storage system based on the received responses.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, the role of voting is assigned to a number of computing clusters. To make this selection, a task assigning service finds a candidate leader and M computing clusters to be used as voters. This selection may be based on finding latencies between the M computing clusters and the leader.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, an indication that a number N of clusters are to be assigned a replica role and a second number M of the replica-role assigned clusters are to be assigned to a voting role. N computing clusters are selected using workload data, and M of the clusters are assigned to a voting role.

Abstract: Methods and systems for monitoring performance in a distributed storage system described. One example method includes identifying requests sent by clients to the distributed storage system, each request including request parameter values for request parameters; generating probe requests based on the identified requests, the probe requests including probe request parameter values for probe request parameter values, representing a statistical sample of the request parameters included in the identified requests; sending the generated probe requests to the distributed storage system over a network, wherein the distributed storage system is configured to perform preparations for servicing each probe request in response to receiving the probe request; receiving responses to the probe requests from the distributed storage system; and outputting at least one performance metric value measuring a current performance state of the distributed storage system based on the received responses.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, an indication that a number N of clusters are to be assigned a replica role and a second number M of the replica-role assigned clusters are to be assigned to a voting role. N computing clusters are selected using workload data, and M of the clusters are assigned to a voting role.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, a leader is selected from among candidate computing clusters. To make this selection, an activity monitor predicts or monitors the workload of one or more clients. Different activities of the workload are given corresponding weights. The delay in performing requested activities, modified by these weights is found, and the candidate leader with the lowest weighted delay is selected as the leader.

Abstract: Replicas are selected in a large distributed network, and the roles for these replicas are identified. In one example, the role of voting is assigned to a number of computing clusters. To make this selection, a task assigning service finds a candidate leader and M computing clusters to be used as voters. This selection may be based on finding latencies between the M computing clusters and the leader.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for receiving a search query that includes a query term from a client device; obtaining first search results for the search query; identifying a candidate expansion of the query term in text associated with the first search results; revising the search query to include the candidate expansion of the query term; and obtaining second search results for the revised search query.

Abstract: A system and method for maintaining a database with a plurality of replicas that are geographically distributed. A plurality of tables are stored in a first replica, each table including a plurality of records. The system identifying if the record is a stub and requesting a lease from a second replica designated as master for the record if the record is a stub. The system receiving a copy of the record from the second replica and storing data fields of the record in the first replica after receiving the lease.

Abstract: A method and system for maintaining a database with a plurality of replicas that are geographically distributed. A plurality of tables are stored in the database, each table includes a plurality of records. The location where each record is stored being controlled based on a constraint property included in the record.

Abstract: A system is described for providing scalable in-memory caching for a distributed database. The system may include a cache, an interface, a non-volatile memory and a processor. The cache may store a cached copy of data items stored in the non-volatile memory. The interface may communicate with devices and a replication server. The non-volatile memory may store the data items. The processor may receive an update to a data item from a device to be applied to the non-volatile memory. The processor may apply the update to the cache. The processor may generate an acknowledgement indicating that the update was applied to the non-volatile memory and may communicate the acknowledgment to the device. The processor may then communicate the update to a replication server. The processor may apply the update to the non-volatile memory upon receiving an indication that the update was stored by the replication server.