1. Computer Science Storage Systems and Sensor Storage Research Overview

2. Computer Science Storage Research Overview Hyperion –High volume stream archival system Bandwidth efficient data migration in enterprise storage systems Use of flash-storage in data centers

3. Computer Science Hyperion Stream Store Streaming data common in environments such as network monitoring, system monitoring, sensors, RFID –Archive data for retrospective querying, forensics Hyperion: high volume stream archival for distributed network monitoring –Gigabit link: 250K packets per second –Archive and index in real-time, while supporting interactive querying –Neither commodity rdbms nor general-purpose file systems suitable [Usenix 2007]

4. Computer Science Hyperion Design Multiple monitor nodes, each monitoring multiple network links StreamFS: high-performance stream file system Local index: multi-level signature index based on bloom filters Distributed index for querying multiple nodes Can scale to million pkts/s with StreamFs and 200K pkts/s indexing per core on a commodity multi-core PC Monitor/ capture StreamFS Signature index Distributed index Hyperion node

5. Computer Science Online Data Migration Enterprise storage systems: multiple volumes mapped onto each array –Load imbalances and hotspots can occur Goal: automatically resolve hotspots on volumes in large storage systems Focus: minimize migration cost (bytes migrated to resolve hotspot) Bandwidth-to-space ratio algorithm –Displace and swap of volumes –Implemented in Linux lvm [ICAC 06]

6. Computer Science Semantic-aware Replication Replication for disaster recovery: synchronous replication for tight recovery point objectives –Latency increases with geographic separation –Use of intermediary does not improve consistency –Too stringent for certain applications Semantic-aware replication: hybrid approach –Use synchronous replication for “important” writes –Use asynchronous replication for other writes –Automatically infer which mode to use for each request –Transparent to applications

7. Computer Science Flash-storage in Data Centers Flash-based storage becoming popular –Higher performance but also higher cost than disk drives How can flash storage be exploited in data centers? Use flash drives as an accelerator between disk storage and servers –Focus on video storage where performance is key Exploit flash disk as non-volatile storage in servers –Fast hibernate / resume => efficient power management in data centers

8. Computer Science Sensor Storage Overview Flash memory becoming extremely energy- efficient Exploit flash memory trends to design more efficient in-network sensor storage and querying systems –Capsule: flash-based object storage system –STONES: storage-centric sensor networks CC1000 CC2420 Telos STM NOR Atmel NOR Communication Storage Micron NAND 128MB Energy Cost (uJ/byte) Generation of Sensor Platform

9. Computer Science Capsule Overview Object-based storage abstraction Energy and memory optimized library of objects Checkpointing and rollback for failure recovery Storage reclamation to deal with finite storage capacity Portable to NAND/NOR flash memories and different sensor platforms [SenSys 06]

10. Computer Science StonesDB Overview Query Engine Partitioned Access Methods StonesDB: flash memory- optimized archival data management architecture that supports sensor data storage, indexing, and aging of data. [CIDR 07]

11. Computer Science Extra Slides

12. Computer Science Mapping App Data Needs to Storage Debug logs Data Archival & Indexing Signal Processing Packet Queue Map application data structures to Capsule objects that offer efficient flash implementation Calibration Tables ? ? Pages on Flash Data Processing Queue Array Stream Stack File Index

13. Computer Science Local Data Management Stack

14. Computer Science Distributed Data Management Stack

15. Computer Science STONES Design an archival data management architecture that: –Supports energy-efficient sensor data storage, indexing, and aging by optimizing for flash memories. –Supports energy-efficient processing of SQL-type queries, as well as data mining and search queries. –Is configurable to heterogeneous sensor platforms with different memory and processing constraints.

16. Computer Science Technology Trends in Storage Generation of Sensor Platform CC1000 CC2420 Telos STM NOR Atmel NOR Communication Storage Micron NAND 128MB Energy Cost (uJ/byte)