Fixes client hangs possible after stopping & restarting an osd.
Hangs happened when a connection was closed in the middle of reading a READ
operation reply from the network. In this case the operation being read was
in read_op and the client didn't free it when closing the connection.
Test case for msgr_read.cpp:
- Partially read reply for a READ operation
- stop_client()
- Check that the READ operation returns EPIPE
The bug was actually introduced in 0.5.11.
etcd connection stability, clang & elbrus support
- Fix build under CLang and Elbrus LCC compilers, making Vitastor compatible
with Elbrus CPUs :)
- Completely fix the bug where OSDs didn't connect to peers and incorrectly marked
PGs as incomplete
- Limit I/O depth for deletes the same way as for small writes. Makes OSD crashes
with "Assertion failed: sqe != NULL" during image deletion go away
- Fix a very old, but rare, journaling bug (credits to https://github.com/mirrorll)
- Fix flushing of unclean journaled objects leading to OSDs sometimes hanging
after failover in EC setups (bug was introduced in 0.6.7)
- Fix several problems that could prevent smooth operation of a Vitastor cluster
under the condition of partial etcd failure:
- OSDs could randomly fail due to too strict error handling
- New clients and OSDs could be unable to start because of the lack of retries
- CLI could fail some commands because of the lack of retries
- Monitor could stop receiving state updates because of the lack of websocket pings
- Fix monitor being unable to rebalance PGs after a downscale of pool pg_size (3->2)
- Exit with failure when trying to nbd map or benchmark a non-existing image
- Use HTTP keep-alive for etcd connections
- Allow to configure etcd request timeouts and retries
- Allow to configure NBD timeout, max devices and partitions, and set default to
up to 64 devices with up to 3 partitions each
Build problems fixed:
- void* pointer arithmetic which is a GNU extension (works as byte*)
- "variable size object may not be initialized" which is OK under GCC
- nullptr_t related error in json11 (it lacks 'operator <' in clang)
Warnings fixed:
- empty nested struct initializer { 0 } replaced by {}
- removed several unused lambda captures
Prelimilary results:
- CPU usage drops significantly. For example, in T1Q8 128K write test against
stub_uring_osd with 10G network and Athlon X4 860k CPU it drops from 100% to 30%
- Latency becomes slightly worse. In T1Q1 4K write test in the same environment
latency increases from 56 to 63 us.
- Small write throughput also becomes slightly worse. In T1Q128 4K write test
against stub iops decreases from 138k to ~110k (unstable, fluctuates 100k..120k).
Note that this is without io_uring, of course.
- Slightly reduce journaling write amplification (requires no_same_sector_overwrites=false)
- Fix listen_backlog (it was 0) because it could more than halve OSD socket send speed
- Support IPv6 OSD addresses
- Do not try to initialize client in simple-offsets
- Fix OSDs sometimes marking PGs incomplete instead of trying to connect with peers
- Allow to configure OSD placement in node_placement
- Allow to run with 4k sector size block devices. Natural, but it was forbidden
Slightly reduces WA. For example, in 4K T1Q128 replicated randwrite tests
WA is reduced from ~3.6 to ~3.1, in T1Q64 from ~3.8 to ~3.4.
Only effective without no_same_sector_overwrites.