Abstract: Implementations of this specification provide methods and apparatuses for replaying logs. One method includes: classifying a plurality of logs to be replayed into log queues, sending the log queues to a global replay queue, allocating one or more replay threads to the log queues based on rankings of the log queues in the global replay queue, wherein the one or more replay threads are configured to replay one or more current log queues of the log queues, and in response to identifying an error of a current log queue of the one or more current log queues in a replay process, allocating a replay thread of the one or more replay threads allocated to the current log queue to a log queue that immediately follows the current log queue in the global replay queue.

Abstract: Lease transfer between master and slave replicas is described. A master replicator determines that an initial master replica lease takes effect. On determining that a master replica transfer needs to be performed, sending a transfer preparation message to a target replicator prior to expiration of a current master replica lease. The target replicator locally starts and calculates a new master replica lease and returns a readiness response to the master replicator. The master replicator sends a lease extension message to remaining slave replicators to extend local corresponding leases. After receiving lease extension success responses of a majority of the slave replicators, the master replicator terminates the local master replica lease of the master replicator in advance, and sends a transfer confirmation message to the target replicator. The target replicator validates the new master replica lease to make the target replicator a new master replicator.

Abstract: Disclosed are a waist structure of a robot. The waist structure includes: a fixed platform, a connector, a movable platform, a load-carrying bearing and two motors arranged on the fixed platform, and two drive assemblies. The connector includes first and second ends facing away from each other; the first end is provided with a yaw shaft connected to an inner ring of the load-carrying bearing; and the second end is provided with a pitch shaft rotatably connected to the movable platform. Each drive assembly corresponds to one motor, and the drive assemblies are connected to the movable platform and the corresponding motors. The motors can actuate the drive assemblies to drive the movable platform to rotate relative to the connector in an axial direction of the pitch shaft and the connector to rotate relative to the fixed platform in an axial direction of the yaw shaft.

Abstract: A portable electronic presentation system is provided with a LCD display panel that is ultrathin, ultralight, and capable of freestanding operation.