Throttling and multiprocessing in secondary server

To keep the data in the primary and secondary servers up-to-date, the primary server writes to its transaction log and forwards the transaction log to the secondary server so that the secondary server can make the same changes to its copy of the database. If the secondary server cannot keep up with the processing pace of the primary server, the solidDB throttling mechanism slows down the processing on the primary server. From the application standpoint, throttling results in increased response times.

The secondary server can use multiple threads for processing the write loads. The secondary server receives operations from the primary server in one stream. Operations are parsed and each transaction is attached to an execution queue; there are as many execution queues as there are open parallel transactions. To ensure that conflicting operations are executed in the correct order, row locks are used.

Perfmon variable	Description
HSB grpcommits	Number of transactions in the most recent group commit. Transaction commits are grouped in one-log bursts which are sent to the secondary server as one packet. You can use this counter only on the primary server.
HSB secondary ops in packet	Number of log records the secondary server received from the primary server in the most recent log record packet.
HSB secondary trx count	Number of open transactions the secondary server has received from the primary server.
HSB secondary locks	Number of row-level locks on the secondary server.
HSB secondary lock reqs	Number of lock requests on the secondary server.
HSB secondary lock waits	Number of lock waits on the secondary server since the server was started.
HSB secondary op waits	Number of times operations (transactions) on the secondary server have been waiting to continue execution.
HSB secondary buffers	Number of buffered log record packets the secondary server has received from the primary server.
HSB secondary serial mode count	Number of times the secondary server parallel executor has switched to serial mode instead of running in parallel.
HSB secondary dispatch queuelength	Size of the most recent dispatch thread (operations to dispatch) on the secondary server.