ODP is slower than regular RDMA even with memory copy overhead
Example numbers:
- 3950000 random read iops without ODP vs 240000 iops with ODP
- 1447000 random write iops without ODP vs 101000 iops with ODP
Reference: https://tkygtr6.github.io/pub/ISPASS21_slides.pdf
New features:
- Implement CSI volume expansion
- Implement CSI volume snapshots
- CSI driver now requires Kubernetes >= 1.20
Bug fixes:
- Important bug fix for EC: fix EC n+k, k>=2 read recovery in ISA-L version returning
incorrect data when reading at least the second chunk out of multiple missing chunks
without reading the first one. All users of EC n+k, k>=2 should upgrade as soon as
possible, and upgrade should be conducted with downtime: first stop all clients
(VMs/containers), then all OSDs, then upgrade and restart everything.
- Fix unstable statistics aggregation in monitor (affecting vitastor-cli status and df)
- Make udev not wait for OSDs to start during boot
- Do not report negative numbers of offline PGs in vitastor-cli status when changing PG count
- Report both old and new PG counts in vitastor-cli df when changing it
- Fix OSDs sometimes not starting with "The code only supports journal versions 1 and 2,
but it is 2 on disk" error after upgrading from pre-1.0 versions and letting OSDs run
for some time
- Fix monitors sometimes returning old PG count back after OSD configuration changes
- Make monitor PG changes more stable and timeout errors less probable
New features:
- Implement [client writeback cache](docs/config/client.en.md#client_enable_writeback)
- Add the third I/O mode: [O_DIRECT|O_SYNC](docs/config/osd.en.md#data_io) (good for Optane)
- Reduce load on etcd by splitting OSD lease and statistics reporting intervals:
[etcd_stats_interval](docs/config/osd.en.md#etcd_stats_interval) (default 30 sec)
- Make MON automatically filter OSDs by layout (block_size/immediate_commit/bitmap_granularity)
to prevent "refusing to start PGs of this pool" errors on misconfiguration
- Support running fio benchmarks on systems without io_uring
- Make QEMU driver compatible with QEMU 8.1
- Document usage of [vhost-user-blk](docs/usage/qemu.en.md#vhost-user-blk)
Bug fixes:
- Fix resizing disks in QEMU driver (for example, in Proxmox)
- Fix "unexpected result" in Proxmox driver by making CLI flush output on exit
- Remove unneeded block_size mismatch warnings on pools without matching PGs
- Fix possible segfault in vitastor-cli ls -l (usually with deleted pools)
- Fix QEMU driver compatibility with systems without io_uring
- Fix monitor eating 100% CPU when etcd is down (caused by infinite retries)
- Fix potential incorrect write processing with snapshots (not caught in tests
but could probably lead to client hangs)
- Fix buffer insertion in cluster_client (not caught in tests but could
probably lead to incorrect writes in rare cases)
- Fix rare OSD crash during sync operation processing
- Fix a reenterability issue in cluster_client not reproducible in QEMU/fio,
but reproducible with the currently developed K/V database implementation
- Fix deletion of the first modified object - OSDs could crash if you modified
the same object a lot of times, then deleted it, and then modified it again
- Fix the fio_sec_osd test tool
- Disabled by default, enable with client_enable_writeback=true
- Even then only enabled in FIO when -direct is disabled and in QEMU when
block device cache is enabled in settings
- Can also be enabled in other clients like vitastor-cli using parameter
client_writeback_allowed=true, but not recommended
Vitaliy Filippov