1 / 10

Effective Quorum Construction for Consistency Management in Mobile Ad Hoc Networks

Effective Quorum Construction for Consistency Management in Mobile Ad Hoc Networks. Takahiro HARA Osaka University, Japan. Rep. Rep. Data Replication in MANETs. Preventing deterioration of data availability at the point of network partitioning. Data replication.

siran
Download Presentation

Effective Quorum Construction for Consistency Management in Mobile Ad Hoc Networks

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. Effective Quorum Construction for Consistency Management in Mobile Ad Hoc Networks Takahiro HARA Osaka University, Japan

  2. Rep. Rep. Data Replication in MANETs • Preventing deterioration of data availability at the point of network partitioning. Data replication. Consistency management among replicas!!

  3. Definition: Consistency • Consistency of data operations on replicas:All read operations can read the latest version of data items (replicas).

  4. Our previous work [IEEE TMC]- Consistency management (1/2) • In a MANET, disappearance of nodes and network partitioning frequently occur. • Read-one, Write-all (Completely synchronized): • Data availability for write operations is very low! Read Write

  5. Our previous work [IEEE TMC]- Consistency management (2/2) • Quorum system • Qi: a set of nodes • Every read operation can access at least a latest replica by performing write/read operations toQW(QR). = Consistency can be maintained. Ex: # of nodes=8, |QW|=5, |QR|=4 Read Write

  6. Our previous work [IEEE TMC]- Consistency management (2/2) • Quorum system • Qi: a set of nodes • Every read operation can access at least a latest replica by performing write/read operations to QW(QR). = Consistency can be maintained. Ex: # of nodes=8, |QW|=5, |QR|=4 Write/read operations can be performed even if some MHs are disconnected. Data availability can be improved ![Karumanchi99, Luo03, Hara05] Read Write

  7. Goal of our work • We address efficient quorum construction and investigate its impact on the system performance. • Investigating the impact of the number of replicas and selection of replica holders (owners) on data availability and traffic.

  8. Effective dynamic quorum construction[Hara’10] • System (changeable) parameters: • kj: The number of MHs having the right to replicate Dj(replica owners) • Dynamic quorums based on the rule|QWj|+ |QRj| > kj • hj: The max. number of MHs in the write quorum to which the write operation is actually performed (kj ≥ hj). • Other nodes in the write quorum store the information on the time stamp and the hjnodes (index of the latest replica holder). How to select kjand hj MHs? Access frequency based approach (kj: static, hj: dynamic)

  9. Performance study (summary) [Hara’10] • Message traffic basically depends on kj (larger kj, higher message traffic). • hj affects the data traffic for both Write/Read. • Write: larger hj, higher data traffic. • Read: larger hj, lower data traffic. • Too small kj shows lower success ratios. kj: Num. of MHs chosen as replica owners hj: Num. of replica owners to which a write is actually performed.

  10. Future directions • Dynamic change of replica owners according to the network topology • Checking periodically the number of replica owners in the majority group and changing replica owners. • Protocol: Quorum-based ? • Quorum construction considering mobility patterns • Node mobility patterns affect the characteristics of network partitioning, e.g., the number of partitions, partition sizes, and their distribution and stability. • We plan to provide some guideline for effectively constructing quorums.

More Related