System and Method for Decoupling Space Reservation in Transactional Logs

Abstract

A common logging system (a “virtual logging system”) that presents to one or more log clients the appearance that each log client is interacting with a dedicated logging system. In reality, the virtual logging system is multiplexing virtual log streams, including log records, for each log client into a single transactional log. In particular, the invention is directed at a system and method for decoupling space reservation between a plurality of distributed components and a core component in the virtual logging system.

1 - 27 . (canceled) 
   
   
       28 . A computer-implemented method comprising:
 providing a function to be called by a client, the function configured to both reserve space and store records to a transactional log;   receiving a communication to the function, the communication including a reference to log records to be stored in the transactional log;   determining whether a sufficient amount of free space exists in the transactional log to append the log records; and   in response to determining there is a sufficient amount of free space, appending the log records to the transactional log, wherein the client has a portion of common reserved space within the transactional log;   in response to determining there is not sufficient amount of free space, appending the log records to pre-reserved space associated with the client and updating an amount of pre-reserved space available to the client.   
   
   
       29 . The computer-implemented method of  claim 28 , wherein updating the amount of pre-reserved space available to the client further comprises reducing the amount of pre-reserved space available to the client by an amount used for appending the log records. 
   
   
       30 . The computer-implemented method of  claim 29 , further comprising communicating the reduced amount of the pre-reserved space to the client. 
   
   
       31 . The computer-implemented method of  claim 28 , further comprising:
 receiving a request by the client to increase the amount of pre-reserved space available to the client;   determining whether to increase the amount of pre-reserved space to the client based at least in part on an amount of free space in the transactional log; and   in response to determining the amount of pre-reserved space is to be increased, increasing the amount of pre-reserved space available to the client.   
   
   
       32 . The computer-implemented method of  claim 31 , further comprising communicating the increased amount of pre-reserved space to the client. 
   
   
       33 . The computer-implemented method of  claim 31 , wherein the request further comprises an indication of a desired amount of pre-reserved space available to the client. 
   
   
       34 . The computer-implemented method of  claim 31 , wherein the increased amount of pre-reserved space is less than the desired amount of pre-reserved space. 
   
   
       35 . The computer-implemented method of  claim 31 , wherein the increased amount of pre-reserved space is more than the desired amount of pre-reserved space. 
   
   
       36 . A computer-implemented method for communicating between a first component and a second component in a transactional logging system, the first component being associated with a client, the method comprising:
 issuing to the second component from the first component, a first message containing an amount of current pre-reserved space and an amount of desired pre-reserved space in a transactional log;   receiving, by the second component, the first message and determining an amount of actual pre-reserved space available to the client in the transactional log; and   issuing, by the second component, a second message identifying the amount of actual pre-reserved space.   
   
   
       37 . The method of  claim 36 , wherein the first message is sent along with another message sent from the first component to the second component. 
   
   
       38 . The method of  claim 37 , wherein the first message is a piggyback message on the other message. 
   
   
       39 . The method of  claim 36 , wherein the second message is sent in conjunction with another message sent from the second component to the first component. 
   
   
       40 . The method of  claim 39 , wherein the second message is a piggyback message on the other message. 
   
   
       41 . The method of  claim 36 , wherein the first component and the second component are implemented on different computers. 
   
   
       42 . The method of  claim 41 , wherein the first message and the second message are issued over a network. 
   
   
       43 . A computer-implemented method for logging data, the method comprising:
 storing data in a plurality of fields, the fields including:
 a first data field comprising log records; 
 a second data field comprising common reserved space, wherein the common reserved space is shared by a plurality of clients; 
 a third data field comprising pre-reserved space. 
   
   
   
       44 . The computer-readable medium of  claim 43 , wherein the pre-reserved space is associated with at least one of the clients. 
   
   
       45 . The computer-readable medium of  claim 43 , further comprising:
 generating an electronic logging message, the electronic message including a first reference to data to be logged and a second reference to a desired amount of pre-reserved space.   
   
   
       46 . The computer-readable medium of  claim 45 , further comprising:
 generating an electronic acknowledgement message in response to the electronic logging message, the electronic acknowledgement message including an indication of whether the desired amount of pre-reserved space is allocated.   
   
   
       47 . The computer-readable medium of  claim 46 , wherein the electronic acknowledgement message further includes an indication of accounting information related to pre-reserved space and common reserved space.