NVMgts

NVMgts is a kind of fast-recoverable hybrid-memory trajectory storage system. It leverage the advantages of both DRAM and Non-Volatile Memory (NVM).

Hardware

DRAM

• Low latency
• Low capacity because of expensive DRAM chip
• Data loss when restart

NVM

• 5-10x latency compared with DRAM
• High capacity
• Persistence even if restarting
• Much faster than SSD

Goals

• Get a higher avaliability than the storage system based on traditional DRAM
• Get a much better performance (e.g., throughput, latency) than systems based on SSD or HDD
• Achieve a better performance than system based on pure NVM
• Support large-scale trajectory dataset through storing data on NVM

System Mode

• pure DRAM: work as an original in-memory trajectory storage on DRAM
• pure NVM: all data are stored on NVM, DRAM is used to process the intermediate results
• hybrid: based on pure NVM, where hot data are transferred to DRAM as a buffer

Operators

clean

make clean

compile

make -jN

run

./test [params..]

restart

./test r

clean all trajectory data on NVM

./test c

change system mode

• pure DRAM: ./test m d
• pure NVM: ./test m s
• hybrid: ./test m h

batch queries through file

first point out the file in main.cpp

then type ./test f

single query through input

first type ./test s

then input RQ(lon1,lon2,lat1,lat2)