Slave side transaction ID buffering for efficient distributed transaction management

Patent metadata

Field	Value
Publication number	US-9635093-B2
Application number	US-201313763920-A
Country	US
Kind code	B2
Filing date	Feb 11, 2013
Priority date	Nov 28, 2012
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

Methods, systems and computer-readable storage mediums encoded with computer programs executed by one or more processors for providing a compressed representation of a transaction token are disclosed. In an embodiment, upon a receipt of a request for a write transaction at a slave server it is determined whether there exists an unassigned transaction identifier (TID) stored locally at the slave server as provided by a master server to the slave server prior to the receipt of the write request by the slave server. If there exists an unassigned TID at the slave server, the slave server is configured to assign the unassigned TID to the write transaction, otherwise the slave server is configured to request a plurality of unassigned TIDs from the master server, receive the plurality of unassigned TIDs, and assign one of the received unassigned TIDs to the write transaction. The write transaction is processed.

First claim

What is claimed is:

1. A method comprising:
determining by a local transaction coordinator (LTC) operating on a slave sever, upon a receipt of a request for a write transaction at the slave server, whether there exists an unassigned transaction identifier (TID) stored locally at the slave server as provided by a master server to the slave server prior to the receipt of the write request by the slave server;
configuring the LTC of the slave server, based on a determination that the unassigned TID exists at the slave server, to:
assign the unassigned TID to the write transaction,
determine that a number of remaining unassigned TIDs, after the configured slave server assigns the TID to the write transaction, is below a threshold, and
request a plurality of unassigned TIDs prior to a receipt of a subsequent write request;

configuring the LTC of the slave server, based on a determination that the unassigned TID does not exist at the slave server, to:
request a plurality of unassigned TIDs from the master server,
receive the plurality of unassigned TIDs locally at the slave server, and
assign one of the received unassigned TIDs to the write transaction; and

processing the write transaction.

2. The method of claim 1 , further comprising:
determining that a number of remaining unassigned TIDs, after the assigning by the configured LTC of the slave server, is below a threshold; and
requesting, from the master server, the plurality of unassigned TIDs upon a receipt of a subsequent write request.

3. The method of claim 1 , further comprising:
determining that the write transaction has completed processing; and
providing an indication to the master server that the write transaction has completed.

4. The method of claim 1 , further comprising:
requesting, prior to the processing, a copy of a transaction token maintained by the master server, indicating which data version of a database is accessible to the write request.

5. The method of claim 1 , wherein the requesting comprises:
determining a number of unassigned TIDs to request; and
requesting the determined number of TIDs.

6. The method of claim 1 , wherein the receiving comprises:
determining that the plurality of received unassigned TIDs includes a sequence of integers.

7. The method of claim 1 , further comprising:
receiving a subsequent plurality of unassigned TIDs from the master server, wherein a number of unassigned TIDs in the plurality of unassigned TIDs varies from a number of unassigned TIDs in the subsequent plurality of unassigned TIDs.

8. The method of claim 1 , wherein the slave server locally buffers one or more unassigned TIDs prior to receiving one or more write requests to which the TIDs are assigned.

9. A system comprising:
a master server including a processor and memory, including a global transaction coordinator (GTC) operating on the master server of a database system;
a slave server including a processor and memory, including a local transaction coordinator (LTC) operating on the slave server of the database system;
the LTC being configured to:
receive a request for a write transaction,
determine, upon the receipt of the request, whether there exists an unassigned transaction identifier (TID) at the slave server as provided by the GTC prior to the receipt of the write request;
based on a determination that the unassigned TID exists at the slave server, the LTC server is configured to:
assign the unassigned TID to the write transaction if there exists the unassigned TID at the slave server,
determine that a number of remaining unassigned TIDs, after the configured slave server assigns the TID to the write transaction, is below a threshold, and
request, from the GTC, a plurality of unassigned TIDs prior to a receipt of a subsequent write request;

based on a determination that the unassigned TID does not exist at the slave server, the LTC server is configured to:
request, from the GTC, a plurality of unassigned TIDs,
receive the plurality of unassigned TIDs at the slave server, and
assign one of the received unassigned TIDs to the write transaction; and

wherein the slave server is configured to process the write transaction after the unassigned TID has been assigned to the write transaction.

10. The system of claim 9 , wherein the LTC is further configured to:
determine that a number of remaining unassigned TIDs, after the assigning by the LTC, is below a threshold; and
request, from the GTC, the plurality of unassigned TIDs upon a receipt of a subsequent write request.

11. The system of claim 9 , wherein the LTC is further configured to:
determine that the write transaction has completed processing; and
provide an indication to the GTC that the write transaction has completed.

12. The system of claim 9 , wherein the LTC is further configured to:
request, prior to the processing, a copy of a transaction token maintained by the GTC, indicating which data version of a database is accessible to the write request.

13. The system of claim 9 , wherein the LTC is configured to request is configured to:
determine a number of unassigned TIDs to request; and
request the number of unassigned TIDs.

14. The system of claim 9 , wherein the LTC is configured to receive the plurality of transaction identifiers is configured to:
determine that the plurality of received unassigned TIDs includes a sequence of integers.

15. The system of claim 9 , wherein the LTC is further configured to:
receive a subsequent plurality of unassigned TIDs from the GTC, wherein a number of unassigned TIDs in the plurality of identifiers varies from a number of unassigned TIDs in the subsequent plurality of unassigned TIDs.

16. The system of claim 9 , wherein the GTC is configured to, upon receiving the request for the plurality of unassigned TIDs, determine how many TIDs to provide to the LTC based on an anticipated workload of the slave server.

17. A non-transitory computer-readable storage device having computer-executable instructions stored thereon, execution of which, by a computing device, causes the computing device to perform operations comprising:
determining by a local transaction coordinator (LTC) operating on a slave sever, upon a receipt of a request for a write transaction at the slave server, whether there exists an unassigned transaction identifier (TID) at the slave server as provided by a master server prior to the receipt of the write request;
configuring the LTC of the slave server, based on a determination that the unassigned TID exists at the slave server, to:
assign the unassigned TID to the write transaction,
determine that a number of remaining unassigned TIDs, after the configured slave server assigns the TID to the write transaction, is below a threshold, and
request a plurality of unassigned TIDs prior to a receipt of a subsequent write request;

configuring the LTC of the slave server, based on a determination that the unassigned TID does not exist at the slave server, to:
request a plurality of unassigned TIDs from the master server,
receive the plurality of unassigned TIDs locally at the slave server, and
assign one of the received unassigned TIDs to the write transaction; and
processing the write transaction.

18. The non-transitory computer-readable storage device of claim 17 having computer-executable instructions stored thereon that cause the LTC of the slave server to assign the unassigned TID to the write transaction based on the determination that the unassigned TID exists at the slave server further co

Assignees

• Lee Juchang
• Park Chang Gyoo
• Na Hyoungjun
• Kim Kyuhwan
• Sap Ag

Inventors

• Lee Juchang
• Park Chang Gyoo
• Na Hyoungjun
• Kim Kyuhwan

Classifications

• G06F17/30356

  Physics · mapped topic

• H04L67/10 Primary

  in which an application is distributed across nodes in the network (software deployment G06F8/60; multiprogramming arrangements G06F9/46) · CPC title

• G06F16/2329 Primary

  using versioning · CPC title