A WAL object was closed by defer, however the WAL was rewritten afterwards,
so defer closed already closed WAL but not the new one. It caused a data
race between writing file and cleaning up a temporary test directory,
which led to a non-deterministic bug.
Fixes#14332
Signed-off-by: Vladimir Sokolov <vsvastey@gmail.com>
For a cluster with only one member, the raft always send identical
unstable entries and committed entries to etcdserver, and etcd
responds to the client once it finishes (actually partially) the
applying workflow.
When the client receives the response, it doesn't mean etcd has already
successfully saved the data, including BoltDB and WAL, because:
1. etcd commits the boltDB transaction periodically instead of on each request;
2. etcd saves WAL entries in parallel with applying the committed entries.
Accordingly, it may run into a situation of data loss when the etcd crashes
immediately after responding to the client and before the boltDB and WAL
successfully save the data to disk.
Note that this issue can only happen for clusters with only one member.
For clusters with multiple members, it isn't an issue, because etcd will
not commit & apply the data before it being replicated to majority members.
When the client receives the response, it means the data must have been applied.
It further means the data must have been committed.
Note: for clusters with multiple members, the raft will never send identical
unstable entries and committed entries to etcdserver.
Signed-off-by: Benjamin Wang <wachao@vmware.com>
Problem: We pass grpc context down to applier in readonly serializable txn.
This context can be cancelled for example due to timeout.
This will trigger panic inside applyTxn
Solution: Only panic for transactions with write operations
fixes https://github.com/etcd-io/etcd/issues/14110
main PR https://github.com/etcd-io/etcd/pull/14149
Signed-off-by: Bogdan Kanivets <bkanivets@apple.com>
Only `net.TCPConn` supports `SetKeepAlive` and `SetKeepAlivePeriod`
by default, so if you want to warp multiple layers of net.Listener,
the `keepaliveListener` should be the one which is closest to the
original `net.Listener` implementation, namely `TCPListener`.
Also refer to https://github.com/etcd-io/etcd/pull/14356
Signed-off-by: Benjamin Wang <wachao@vmware.com>
This changes the default parent-based trace sampling rate from
100% to 0%. Due to the high QPS etcd can handle, having 100% trace
sampling leads to very high resource usage. Defaulting to 0% means
that only already-sampled traces will be sampled in etcd.
Fixes#14310
Signed-off-by: Mike Dame <mikedame@google.com>
Currently the max size of each WAL entry is hard coded as 10MB. If users
set a value > 10MB for the flag --max-request-bytes, then etcd may run
into a situation that it successfully processes a big request, but fails
to decode it when replaying the WAL file on startup.
On the other hand, we can't just remove the limitation, because if a
WAL entry is somehow corrupted, and its recByte is a huge value, then
etcd may run out of memory. So the solution is to restrict the max size
of each WAL entry as a dynamic value, which is the remaining size of
the WAL file.
Signed-off-by: Benjamin Wang <wachao@vmware.com>
The first bug fix is to resolve the race condition between goroutine
and channel on the same leases to be revoked. It's a classic mistake
in using Golang channel + goroutine. Please refer to
https://go.dev/doc/effective_go#channels
The second bug fix is to resolve the issue that etcd lessor may
continue to schedule checkpoint after stepping down the leader role.
we found a lease leak issue:
if a new member(by member add) is recovered by snapshot, and then
become leader, the lease will never expire afterwards. leader will
log the revoke failure caused by "invalid auth token", since the
token provider is not functional, and drops all generated token
from upper layer, which in this case, is the lease revoking
routine.
When clients have no permission to perform whatever operation, then
the applying may fail. We should also move consistent_index forward
in this case, otherwise the consitent_index may smaller than the
snapshot index.
