Email server with enhanced least recently used (LRU) cache

• US 8,307,036 B2
• Filed: 09/27/2005
• Issued: 11/06/2012
• Est. Priority Date: 09/27/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Kamat, Harshad N., Clarke, David J.
• Primary Examiner(s): Neurauter, George C
• Assistant Examiner(s): Mesa, Joel
• Application Number:
  US11/235,768
• Publication Number:
  US 20070073813A1
• Time in Patent Office: 2,597 Days
• Field of Search: 709/206, 709/207
• US Class Current: 709/206
• CPC Class Codes: H04L 51/00 User-to-user messaging in packet-switching networks, transmitted according to store-and-forward or real-time protocols, e.g. e-mail
• CPC Class Codes: H04L 51/42 Mailbox-related aspects, e.g. synchronisation of mailboxes

Abstract

An electronic mail (email) server includes a proxy that obtains mappings for unique identifiers (UID'"'"'s) corresponding to new electronic messages that have been determined from a polling operation. A Least Recently Used (LRU) cache caches each new message and releases from cache least recently used messages. A memory in which all messages within the LRU cache are spooled.

Claims

1. An electronic mail (email) server comprising:

a proxy that obtains mappings for message identifiers (MsgID'"'"'s) corresponding to new electronic messages that had been determined from a polling operation;

a least recently used (LRU) cache that caches the MsgID'"'"'s and a predetermined size of each new electronic message corresponding to the MsgID'"'"'s and releases from the LRU cache the least recently used MsgID and predetermined size of the new electronic message corresponding to the MsgID; and

a memory in which all messages within the LRU cache are saved;

the proxy receives a mail job, determines if a MsgID for the mail job is in the cache, and if yes, obtains a mapping for the MsgID from the cache and processes the mail job, if the MsgID for the mail job is not in the cache, retrieves the MsgID from a database, caches the retrieved MsgID into the cache, obtains a mapping for the retrieved MsgID from the cache and processes the mail job, and purges without using weights and heuristics the cache of the MsgID'"'"'s.

2. The email server according to claim 1, wherein said memory comprises a disk memory having an input/output through which the new electronic messages are input and output.

3. The email server according to claim 2, wherein said input/output varies in its request per second based on the number of said proxies per partition.

4. The email server according to claim 3, wherein said input/output has fewer requests per second when a greater number of said proxies per partition exist on the disk memory.

5. The email server according to claim 1, wherein said proxy is operative for filtering out received headers from a new electronic message to aid in reducing an overall size of a new electronic message.

6. An electronic mail (email) server comprising:

a least recently used (LRU) cache that caches the MsgID'"'"'s and a predetermined size of each new electronic message corresponding to the MsgID'"'"'s as determined from a polling operation and releases from the LRU cache the least recently used MsgID and predetermined size of the new electronic message corresponding to the MsgID;

a disk memory in which all new electronic messages within the LRU cache are saved; and

a proxy that receives a mail job, determines if a MsgID for the mail job is in the cache, and if yes, obtains a mapping for the MsgID from the cache and processes the mail job, if the MsgID for the mail job is not in the cache, retrieves the MsgID from a database, caches the retrieved MsgID into the cache, obtains a mapping for the retrieved MsgID from the cache and processes the mail job, and purges without using weights and heuristics the cache of the MsgID'"'"'s.

7. The email server according to claim 6, wherein said disk memory includes an input/output through which the new messages are input and output.

8. The email server according to claim 7, wherein said input/output varies in its request per second based on the number of said proxies per partition.

9. The email server according to claim 8, wherein said input/output has fewer request per second when a greater number of said proxies per partition exist on the disk memory.

10. A communication system comprising:

a polling engine that polls an electronic mailbox of a user to retrieve message identifiers (MsgID'"'"'s) of new messages;

a proxy that obtains mappings for the new message;

a least recently used (LRU) cache that caches the MsgID'"'"'s and a predetermined size of each of the new messages corresponding to the MsgID'"'"'s and releases from the LRU cache the least recently used MsgID and predetermined size of the new message corresponding to the MsgID; and

a memory in which all new messages within the LRU cache are saved;

the proxy receives a mail job, determines if a MsgID for the mail job is in the cache, and if yes, obtains a mapping for the MsgID from the cache and processes the mail job, if the MsgID for the mail job is not in the cache, retrieves the MsgID from a database, caches the retrieved MsgID into the cache, obtains a mapping for the retrieved MsgID from the cache and processes the mail job, and purges without using weights and heuristics the cache of the MsgID'"'"'s.

11. The communications system according to claim 10, wherein said memory comprises a disk memory having an input/output through which the new messages are input and output.

12. The communications system according to claim 11, wherein said input/output varies in its request per second based on the number of said proxies per partition.

13. The communications system according to claim 12, wherein said input/output has fewer request per second when a greater number of said proxies per partition exist on the disk memory.

14. The communications system according to claim 12, wherein said proxy is operative for filtering out received headers from a new message to aid in reducing an overall size of a new message.

15. An electronic mail (email) processing method, which comprises:

polling an electronic mailbox of a user to retrieve message identifiers (MsgID'"'"'s) of new messages;

obtaining mappings for the new messages;

caching the MsgID'"'"'s and a predetermined size of each new message corresponding to the MsgID'"'"'s within a least recently used (LRU) cache;

releasing the least recently used MsgID and predetermined size of the new message corresponding to the MsgID from the LRU cache;

saving all messages within the LRU cache to memory; and

receiving a mail job within a proxy and determining if a MsgID for the mail job is in the cache, and if yes, obtaining a mapping for the MsgID from the cache and processing the mail job, and if the MsgID for the mail job is not in the cache, retrieving the MsgID from a database, caching the retrieved MsgID into the cache, obtaining a mapping for the retrieved MsgID from the cache and processing the mail job, and purging without using weights and heuristics the cache of the MsgID'"'"'s.

16. A method according to claim 15, which further comprises spooling all new messages to a disk memory.

17. A method according to claim 16, which further comprises varying the requests per second in and out of the disk memory based on a proxy per partition.

18. A method according to claim 15, which further comprises filtering out received headers from a new message to aid in reducing an overall size of new message.

19. A computer-readable medium having computer-executable modules comprising:

a least recently used (LRU) cache that caches the MsgID'"'"'s and a predetermined size of each of the new electronic messages corresponding to the MsgID'"'"'s as determined from a polling operation and releases from the LRU cache the least recently used MsgID and predetermined size of the new electronic message corresponding to the MsgID;

a memory in which all messages within the LRU cache are saved; and

a proxy that receives a mail job, determines if a MsgID for the mail job is in the cache, and if yes, obtains a mapping for the MsgID from the cache and processes the mail job, if the MsgID for the mail job is not in the cache, retrieves the MsgID from a database, caches the retrieved MsgID into the cache, obtains a mapping for the retrieved MsgID from the cache and processes the mail job, and purges without using weights and heuristics the cache of the MsgID'"'"'s.

20. A computer-readable medium according to claim 19, wherein the memory comprises a disk memory.