1 / 7

Gnutella Crawler

Gnutella Crawler. Group 1 (Calvin Ching , Levi Stoddard, Kelvin Tsui). Overall System Design. master-slave architecture communication: master-slave: NIO  master-master: blocking IO leader election: bully election algorithm based on version number and host name replication:

nora
Download Presentation

Gnutella Crawler

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Gnutella Crawler Group 1 (Calvin Ching, Levi Stoddard, Kelvin Tsui)

  2. Overall System Design • master-slave architecture • communication: • master-slave: NIO  • master-master: blocking IO • leader election: • bully election algorithm • based on version number and host name • replication: • primary master replicates data to 5 backups • performs write to disk • every 10 seconds

  3. Overall System Design Diagram

  4. Handling Master Node Failures • redirection message • sent from a backup master when slave tries to contact it for nodes to crawl or submit • occurs when slave fails to contact the primary master • a new election begins to ensure that a correct primary master is chosen • whenever a master node comes back online, a new election begins • a restarted node may become the primary master, or may become a backup master

  5. Crawler Performance • 6 masters, 84 slaves (119 attempted) • 30 minutes (including deployment time)  • master - < ~140MB memory usage • Number of Peers Crawled/Discovered: • 55905 crawled successfully • 851811 discovered but not crawled • 111082 other (failed) • 1018798 total  • Rate of Crawling/Discovered (peers/second) • 31.06 crawled successfully • 473.22 discovered but not crawled • 565.99 overall 

  6. Issues We Encountered • At certain nodes, some specific ports are being used by other processes • eg. election port = 4444 at earth.cs.brown.edu  • Amount of data that was sent from slaves to master had to be capped • insufficient buffer? • network bottlenecks?

  7. Questions?

More Related