reordering won't make the actual write to be committed before marking
the coresponding extent as dirty.
It can be disabled in configuration file.
If BIO_FLUSH is not supported by the underlying file system we log a warning
and never send BIO_FLUSH again to that GEOM provider.
MFC after: 3 days
disk if needed. This should fix a potential case when extents are cleared in
activemap but metadata is not updated on disk.
Suggested by: pjd
Approved by: pjd (mentor)
stating if we need to update activemap on disk. This makes keepdirty
serve its purpose -- to reduce number of metadata updates.
Discussed with: pjd
Approved by: pjd (mentor)
only receiving the data. In r220271 the unused directions were
disabled using shutdown(2).
Unfortunately, this broke automatic receive buffer sizing, which
currently works only for connections in ETASBLISHED state. It was a
root cause of the issue reported by users, when connection between
primary and secondary could get stuck.
Disable the code introduced in r220271 until the issue with automatic
buffer sizing is not resolved.
Reported by: Daniel Kalchev <daniel@digsys.bg>, danger, sobomax
Tested by: Daniel Kalchev <daniel@digsys.bg>, danger
Approved by: pjd (mentor)
MFC after: 1 week
sending. What happens otherwise is that the sender splits all the
traffic into 32k chunks, while the receiver is waiting for the whole
packet. Then for a certain packet sizes, particularly 66607 bytes in
my case, the communication stucks to secondary is expecting to
read one chunk of 66607 bytes, while primary is sending two chunks
of 32768 bytes and third chunk of 1071. Probably due to TCP windowing
and buffering the final chunk gets stuck somewhere, so neither server
not client can make any progress.
This patch also protect from short reads, as according to the manual
page there are some cases when MSG_WAITALL can give less data than
expected.
MFC after: 3 days
requests as well as number of activemap updates.
Number of BIO_WRITEs and activemap updates are especially interesting, because
if those two are too close to each other, it means that your workload needs
bigger number of dirty extents. Activemap should be updated as rarely as
possible.
MFC after: 1 week
because we need to do ioctl(2)s, which are not permitted in the capability
mode. What we do now is to chroot(2) to /var/empty, which restricts access
to file system name space and we drop privileges to hast user and hast
group.
This still allows to access to other name spaces, like list of processes,
network and sysvipc.
To address that, use jail(2) instead of chroot(2). Using jail(2) will restrict
access to process table, network (we use ip-less jails) and sysvipc (if
security.jail.sysvipc_allowed is turned off). This provides much better
separation.
MFC after: 1 week
hastd process and workers, remove unused one and set different range
of numbers. This is done in order not to confuse them with HASTCTL_CMD
defines, used for conversation between hastctl and hastd, and to avoid
bugs like the one fixed in in r221075.
Approved by: pjd (mentor)
MFC after: 1 week
secondary role. It is possible that the remote node is primary, but only
because there was a role change and it didn't finish cleaning up (unmounting
file systems, etc.). If we detect such situation, wait for the remote node
to switch the role to secondary before accepting I/Os. If we don't wait for
it in that case, we will most likely cause split-brain.
MFC after: 1 week
- We have two nodes connected and synchronized (local counters on both sides
are 0).
- We take secondary down and recreate it.
- Primary connects to it and starts synchronization (but local counters are
still 0).
- We switch the roles.
- Synchronization restarts but data is synchronized now from new primary
(because local counters are 0) that doesn't have new data yet.
This fix this issue we bump local counter on primary when we discover that
connected secondary was recreated and has no data yet.
Reported by: trociny
Discussed with: trociny
Tested by: trociny
MFC after: 1 week
hast_proto_recv_hdr() may be used. This also fixes the issue
(introduced by r220523) with hastctl, which crashed on assert in
hast_proto_recv_data().
Suggested and approved by: pjd (mentor)
