Previously, if multiple metadata messages were written without clearing
transaction state between them, an issue could occur when deserializing
where a later message could be missing its LogProtocolMessage prefix.
This would cause the protocol version to not be set, causing an
assertion failure when deserializing MutationRefs.
This introduces unhygenic macro variants that inline a `ENABLED &&`
before the TraceEvent. This way, they get entirely compiled out unless
enabled.
Then rewrite all debugMutation uses via sed.
Like:
* Leaving the proxy
* Entering the TLog
* Leaving the TLog
* Being read on a cursor
All of this brought to you by TagsAndMessage!
This also slides in a minor optimization as to how mutations are serialized per target log.
Since tlog is not kept until backup worker has pulled mutations from it, the
old tlogs can only be displaced after oldest backup epoch equals current epoch.
So if master is not recruiting backup workers, it should set the oldest backup
epoch as the current epoch.
The start version of tlog set can be smaller than the last epoch's end version.
In this case, set backup worker's start version as last epoch's end version to
avoid overlapping of version ranges among backup workers.
The start version of tlog set can be smaller than the last epoch's end version.
In this case, set backup worker's start version as last epoch's end version to
avoid overlapping of version ranges among backup workers.
Get rid of the complex logic of choosing the largest saved version from
previous epoch for the oldest epoch. Instead, use the begin version now
available from log system.
Sometimes the backup worker has not updated progress to the system space and a
master recovery happens. As a result, next epoch doesn't know the progress of
previous ones. This change is to check for such missing gaps and fill them with
the whole range [startVersion, endVersion).
The code is refactored into BackupProgress.actor.* to consolidate backup
progress processing for the master server.
For backup workers working on old epochs, once their work is done, they will
notify the master. Then the master removes them from the log system and
acknowledge back to the backup workers so that they can gracefully shut down.
The popping of a backup worker is stalled if there are workers from older
epochs still working. Otherwise, workers from old epochs will lost data.
However, allowing newer epoch to start backup can cause holes in version ranges.
The restore process must verify the backup progress to make sure there are no
holes, otherwise it has to wait.
For each log router ID, we track the popped version of each pseudo tag so that
the popping only applied to the minimum of these versions.
Also add more tracing for popping and epochs.
This fixes#1214
The basic idea is that ProtocolVersion is now its own type. This
alone is an improvement as it makes many things more typesafe. For
each version, we can now add breaking features (for example Fearless).
After that, there's no need to test against actual (confusing) version
numbers. Instead a developer can simply test
`protocolVersion->hasFearless()` and this will return true iff the
protocolVersion is newer than the newest version that didn't support
fearless.
In Tlogs, disable pop is done whlie taking snapshots. Earlier, tlogs
were ignoring the pops if it got pop requests when pops were
disabled. In this change, instead of ignoring the pop - it remembers
the list of pops in-memory and plays them once the popping is
enabled.
- exec operation to go to all the TLogs
- minor bug fix in tlog
- restore implementation for the simulator
- restore snap UID to be stored in restartInfo.ini
- test cases added
- indentation and trace file fixes
If a peek is entirely fulfilled from spilled data, then it's likely that
the next peek will be also. It is thus wasteful for each of these peeks
to call peekMessagesFromMemory, which memcpy's excessively, and then
throw all that data away without using it.
Now, TLogs will give a hint back to peek cursors about if the provided
reply was served entirely from the spilled data, which peek curors then
feed back as the hint into their next request.
At some point, a cursor will send a request for only spilled data, get
an incomplete response, and then be told to send its next request as one
that peeks from memory as well, and then it will fully catch up.
This changes the logic of pop operations from log routers (LG):
- LG pops tagLocalityLogRouterMapped from TLogs;
- TLog converts tagLocalityLogRouterMapped back to tagLocalityLogRouter before
popping.
Later when we add more psuedo localities, the same pattern can be used.
* log_version in the database (`/conf/log_version`) is now a hint that gets
rounded to the nearest supported version.
* fdbcli and FDB enforce that only a valid log_version can be configured to
* TLogVersion is persisted in CoreTLogSet (and LogSet and TLogSet)
* Some comments here and there
* Add an assert on filename length to make sure KV-pairs in filename
don't exceed a maximum length.
Remove the use of relative paths. A header at foo/bar.h could be included by
files under foo/ with "bar.h", but would be included everywhere else as
"foo/bar.h". Adjust so that every include references such a header with the
latter form.
Signed-off-by: Robert Escriva <rescriva@dropbox.com>
Richard Chen