DecLog

This is the source code of DecLog.

Our paper, "DecLog: Decentralized Logging in Non-Volatile Memory for Time Series Database Systems", is submitted to VLDB2024.

Introduction

DecLog is decentralized logging system in NVM for TSDBMS by utilizing the characteristics of time series data to improve the logging performance. We implement it based on a time series storage engine of Facebook, Beringei. The experimental study shows that the throughput of DecLog outperforms the Beringei TSDBMS by up to 4.6× with less recovery time in the YSCB-TS benchmark.

Compared with original Beringei, DecLog has following features:

• We propose a data-driven LSN based on the data accessed by transactions and track the transaction dependencies.
• We design a relaxed ordering strategy to persist log entries to NVM by using log flushing pipeline, which effectively addresses the transaction serialization issue caused by a heavy use of sfence instructions.
• We propose a thread snapshot based parallel logging method to further improve the concurrency of persisting logs to NVM in multi-threads with less thread synchronization overhead.
• We design a log compression and alignment algorithm to process the logs to decrease the log storage footprint and to fully utilize NVM properties.
• We implement checkpoint and recovery algorithms of DecLog to reduce the recovery time.

Experiments

• DecLog: The compelete implementation of DecLog.
• DecLog-SSD: DecLog, but with logging in SSD.
• Beringei-NVM: The original implementation of Beringei with logging in NVM.
• Beringei-SSD: The original implementation of Beringei with logging in SSD.

Directory Description

• YCSB-TS： The source code for the benchmark, YCSB-TS developed with Java.
• beringei： The source code for DecLog, implemented based on Beringei with C++.
• install： Some scripts and packages, used to build the environment and DecLog.

Build DecLog

PMDK should be installed. The ipmctl should be installed before building DecLog. Copy Beringei to workspace.

$ unzip ./install/ALL.zip
$ sudo ./install/setup_ubuntu.sh

Build YCSB-TS

YCSB-TS is a maven project and is compiled with JDK1.7. To build it, run maven command mvn clean package. Then uncompress the release package

$ mv ./YCSB-TS/distribution/target/ycsb-0.4.0.tar.gz ./ycsb-0.4.0.tar.gz
$ tar -zxvf ./ycsb-0.4.0.tar.gz

Before Run

You should mount your PMEM* to a NVM-aware filesystem with DAX.

$ sudo mkfs.xfs /dev/pmem0
$ sudo mkdir /mnt/pmem0
$ sudo mount -o dax /dev/pmem0 /mnt/pmem0
$ sudo modprobe msr

Make directorys for data file, key list file, and log file in SSD

$ mkdir /tmp/gorilla_data
$ mkdir /tmp/key
$ mkdir /tmp/log

You can generate a beringei configuration file or modify hostAddress in the configuration file ./beringei/beringei.json.

sudo ./beringei/beringei/build/beringei/tools/beringei_configuration_generator --host_names $(hostname) --file_path $(filePath)

Run DecLog

$ ./beringei/beringei/build/beringei/service/beringei_main \
        -beringei_configuration_path ./beringei/beringei.json \
        -create_directories \
        -bucket_size 600 \
        -buckets 120 \
        -logtostderr \
        -v=2 \
        -port 9997 \
        -shards 8 \
        -data_directory /tmp/gorilla_data \
        -key_directory /tmp/key/ \
        -log_directory /mnt/pmem \
        -log_writer_queue_size 300 \
        -log_writer_threads 4

Run DecLog-SSD

$ ./beringei/beringei/build/beringei/service/beringei_main \
        -beringei_configuration_path ./beringei/beringei.json \
        -create_directories \
        -bucket_size 600 \
        -buckets 120 \
        -logtostderr \
        -v=2 \
        -port 9997 \
        -shards 8 \
        -data_directory /tmp/gorilla_data \
        -key_directory /tmp/key/ \
        -log_directory /tmp/log/ \
        -log_writer_queue_size 300 \
        -log_writer_threads 4
        -NVM_address_aligned 0 \
        -number_of_logging_queues 1 \
        -data_log_buffer_size 65536

Run Beringei-NVM

$ ./beringei/beringei/build/beringei/service/beringei_main \
        -beringei_configuration_path ./beringei/beringei.json \
        -create_directories \
        -bucket_size 600 \
        -buckets 120 \
        -logtostderr \
        -v=2 \
        -port 9997 \
        -shards 8 \
        -data_directory /tmp/gorilla_data \
        -key_directory /tmp/key/ \
        -log_directory /mnt/pmem \
        -log_writer_queue_size 300 \
        -log_writer_threads 1
        -Beringei_NVM 1 \
        -NVM_address_aligned 0 \
        -number_of_logging_queues 1

Run Beringei-SSD

$ ./beringei/beringei/build/beringei/service/beringei_main \
        -beringei_configuration_path ./beringei/beringei.json \
        -create_directories \
        -bucket_size 600 \
        -buckets 120 \
        -logtostderr \
        -v=2 \
        -port 9997 \
        -shards 8 \
        -data_directory /tmp/gorilla_data \
        -key_directory /tmp/key/ \
        -log_directory /tmp/log/ \
        -log_writer_queue_size 300 \
        -log_writer_threads 1
        -Beringei_NVM 1 \
        -NVM_address_aligned 0 \
        -number_of_logging_queues 1 \
        -data_log_buffer_size 65536

Run the benchmark, YCSB-TS

$ ${jdk_dir}/bin/java \
        -classpath ./ycsb-0.4.0/lib/core-0.4.0.jar:./ycsb-0.4.0/beringei-binding/lib/beringei-binding-0.4.0.jar:./ycsb-0.4.0/beringei-binding/lib/slf4j-api-2.0.5.jar:./ycsb-0.4.0/beringei-binding/lib/slf4j-simple-2.0.5.jar:./ycsb-0.4.0/thrift/thriftjava-1.0-SNAPSHOT.jar com.yahoo.ycsb.Client \
        -db com.yahoo.ycsb.db.BeringeiDBClient -load -P ./ycsb-0.4.0/workloads/workloada -p host=$IP -p port=9997 -p shardCount=4 -s -threads 64 &> /dev/null
$ ${jdk_dir}/bin/java \
        -classpath ./ycsb-0.4.0/lib/core-0.4.0.jar:./ycsb-0.4.0/beringei-binding/lib/beringei-binding-0.4.0.jar:./ycsb-0.4.0/beringei-binding/lib/slf4j-api-2.0.5.jar:./ycsb-0.4.0/beringei-binding/lib/slf4j-simple-2.0.5.jar:./ycsb-0.4.0/thrift/thriftjava-1.0-SNAPSHOT.jar com.yahoo.ycsb.Client \
        -db com.yahoo.ycsb.db.BeringeiDBClient -P ./ycsb-0.4.0/workloads/workloada -p host=$IP -p port=9997 -p shardCount=4 -s -threads 64 > workloada_output.txt