ZapRAID

What's Inside

• zapraid_prototype, storing the prototype itself, implemented with C++
• mysql, the folder prepared for TPCC workload in MySQL
• scripts, the scripts to install the prototype and SPDK
• patches, storing our modifications to SPDK and FEMU

Building Guide

• Be sure to read this building guide before proceeding, and be sure to read every scripts before running it when doing experiments.

• ZapRAID SPDK (can also check scripts/one_in_all_install.sh)

  • Build spdk without zapraid first; configure with "--without-zapraid"
  • Build zapraid_prototype; specify the SPDK_DIR in src/CMakeLists.txt
    • cd zapraid_prototype; cmake -Bbuild; cd build; make;
  • Build spdk again with zapraid; configure with "--with-zapraid=DIR"
  • Check scripts in scripts/ for running spdk fio and real applications

• ZapRAID FEMU

  • run patches/cp_femu_files.sh to clone the FEMU repository and put the modified files
  • Follow the FEMU build guide

Experiment scripts

• Check zapraid_prototype/scripts.
  • Notes: Remember to format the SSDs (check zapraid_prototype/scripts/format.sh) and attach the SSDs to the SPDK (run spdk/scripts/setup.sh) before you run the experiments.

Explanations on the parameters

We have several parameters in the json files. Here is the explanations on the parameters. You do not need to change other parameters.

• block_size: The block size of the ZNS SSD. It should be either 512 or 4096.
• unit_size_str: The unit sizes of each open segment, delimited by :. For example, if there are two open segments with unit sizes of 4096 and 8192, the parameter should be "4096:8192".
• num_blocks: The total number of logical blocks in the ZNS RAID.
• system_mode: 0 for ZoneWrite-Only, 1 for ZoneAppend-Only, and 2 for ZapRAID.
• num_data_blocks: The number of data chunks in a stripe, i.e., k for a (k, m) code.
• num_parity_blocks: The number of parity chunks in a stripe, i.e., m for a (k, m) code.
• raid_level: 0 for RAID-0, 5 for RAID-01, 2 for RAID-4, 3 for RAID-5, 4 for RAID-6.
• enable_gc: 0 to disable GC, 1 to enable GC.
• sync_group_size_str: The stripe group sizes of each open segment, delimited by :. For example, if there are two open segments with stripe group sizes of 256 and 1, the parameter should be "256:1".
• num_open_segments: The number of open segments.
• inject_degraded_read: 0 to disable degraded reads, 1 to enable degraded read.
• enable_event_framework: 0 to disable event framework, 1 to enable event framework. This parameter is set for the NVMe-oF object.