There are two Accurev streams, A and B. B is the child of A.
Feature X was mistakenly ported into stream B at one point. Some time later, this was noticed and it was decided to move feature X to another stream to correct the issue. The transaction T for feature X was sent to another stream and reverted in stream B.
So far so good, but there were other files that became modified in stream B only in support of feature X. The problem I'm having is that there seems to be no way of abandoning the version of an element in stream B and reverting to the parent stream A's version, as if the file had never been changed in stream B. Trying to fix this by copying versions resulted in a big mess.
Is is possible to "revert to parent" for a file?
Related
I have two client programs which are using S3 to communicate some information. That information is a list of files.
Let's call the clients the "uploader" and "downloader":
The uploader does something like this:
upload file A
upload file B
upload file C
upload a SUCCESS marker file
The downloader does something lie this:
check for SUCCESS marker
if found, download A, B, C.
else, get data from somewhere else
and both of these programs are being run periodically. The uploader will populate a new directory when it is done, and the downloader will try to get the latest versions of A,B,C available.
Hopefully the intent is clear — I don't want the downloader to see a partial view, but rather get all of A,B,C or skip that directory.
However, I don't think that works, as written. Thanks to eventual consistency, the uploader's PUTs could be reordered into:
upload file B
upload a SUCCESS marker file
upload file A
...
And at this moment, the downloader might run, see the SUCCESS marker, and assume the directory is populated (which it is not).
So what's the right approach, here?
One idea is for the uploader to first upload A,B,C, then repeatedly check that the files are stored, and only after it sees all of them, then finally write the SUCCESS marker.
Would that work?
Stumbled upon similar issue in my project.
If the intention is to guarantee cross-file consistency (between files A,B,C) the only possible solution (purely within s3) is:
1) to put them as NEW objects
2) do not explicitly check for existence using HEAD or GET request prior to the put.
These two constraints above are required for fully consistent read-after-write behavior (https://aws.amazon.com/about-aws/whats-new/2015/08/amazon-s3-introduces-new-usability-enhancements/)
Each time you update the files, you need to generate a unique prefix (folder) name and put this name into your marker file (the manifest) which you are going to UPDATE.
The manifest will have a stable name but will be eventually consistent. Some clients may get the old version and some may get the new one.
The old manifest will point to the old “folder” and the new one will point the new “folder”. Thus each client will read only old files or only new files but never mixed, so cross file consistency will be achieved. Still different clients may end up having different versions. If the clients keep pulling the manifest and getting updated on change, they will eventually become consistent too.
Possible solution for client inconsistency is to move manifest meta data out of s3 into a consistent database (such as dynamo db)
A few obvious caveats with pure s3 approach:
1) requires full set of files to be uploaded each time (incremental updates are not possible)
2) needs eventual cleanup of old obsolete folders
3) clients need to keep pulling manifest to get updated
4) clients may be inconsistent between each other
It is possible to do this single copies in S3. Each file (A B C) will have prepended to it a unique hash or version code [e.g. md5sum generated from the concatenation of all three files.]
In addition the hash value will be uploaded to the bucket as well into a separate object.
When consuming the files, first read the hash file and compare to the last hash successfully consumed. If changed, then read the files and check the hash value within each. If they all match, the data is valid and may be used. If not, the downloaded files should be disgarded and downloaded again (after a suitable delay)..
This will catch the occassional race condition between write and read across multiple objects.
This works because the hash is repeated in all objects. The hash file is actually optional, serving as a low-cost and fast short cut for determining if the data is updated.
I'm a brand new to Accurev and I'm having many troubles with it. One of the developers I'm working with has promoted bad code (things are now broken that weren't before) for 2 months on a stream, and I'm wanting to get a copy of the original code before any changes were made to it.
I currently have a workspace, and whenever the other developer creates code, I pull his changes into this workspace attempting to fix the bugs. These changes are promoted to an existing issue within Accurev.
Is there any way I can perhaps create a second workspace and obtain a copy of the original code (before any changes were made)? My target date is March 14th.
I would suggest you revert or demote the bad code that was promoted into the stream (Depending on what version of AccuRev you are using). This would put the stream back into the state it was before the promotion occurred.
Below are some suggested readings on the related topics.
Best way to "un-promote" files in Accurev?
https://community.microfocus.com/borland/managetrack/accurev/w/wiki/26745/purge-revert-and-demote
https://community.microfocus.com/borland/managetrack/accurev/w/accurev_knowledge_base/25951/how-to-revert-changes-in-a-stream
https://community.microfocus.com/borland/managetrack/accurev/w/accurev_knowledge_base/26079/what-is-the-proper-way-to-revert-by-change-package
As an alternative, you could create a time-based stream below the one with the bad code. Set a time basis that predates the bad promote.
To do this, I right-clicked the stream >> New Snapshot.
I select "Specified" and enter the date (with a relative time).
From the Snapshot, I created a New Workspace which was then populated with previous code.
Hope this helps!
I am using FSEventsFramework to monitor directories for changes. I was wondering if my logic here is sound, for detecting old file name and new name after a rename.
I think on rename, both events are in the same callback.
Old file name will have event id X-1
New file name will have even id X
Is this true?
Thanks
As far as I experienced it, your assumption is not always true. On FSEventStreamCreate you will pass a latency as well as a flag for the meaning of the latency kFSEventStreamCreateFlagNoDefer. Therefore the events may or may not come in the same callback. Furthermore there are different ways the file can be renamed. Some Filesystem-APIs actually rename the file while keeping the inode like mv, others like NSDocument create a new inode. Sometimes you will receive kFSEventStreamEventFlagItemRenamed in the callback, sometimes not.
EDIT: Alternatives to FSEvents are Kernel Queues and NSFileCoordinator
FSEvents are somehow not fully documented in the API-Docs. Have a look at the header file FSEvent.h, there is more to read there.
Then to easily see what is going on for a rename, run your app and do some renaming with Finder, with terminal mv as well as in a document based app using the small triangle right to the filename.
I am working with Accurev and recently I was forced to perform a revert on a recent promote. I followed the general guidelines, accessed the stream's history and performed a revert action on a selected transaction.
That particular transaction involved already existent files but also new ones.
Now here comes the main problem: after the revert the existent files were returned to their previous version but the files that were at their first version appeared in the root of the stream regardless of the path where they were initially placed and were in the state Defunct. Of course this mainly visually disturbing but I am also wondering what will happen later on when someone will try to readd those same files to the stream.
Will there be a conflict, will they be repositioned where they were initially added? At this point I am thinking about reverting the revert action but it already seems really overcomplicated and it look like it would only generate more problems.
Lets say you have a stream hierarchy of: Stream1 - Stream2 - Workspace1
In this hierarchy you have a file called foo.c.
In Stream2, this file has a defunct status.
If you add foo.c to source control in a Workspace1 and promote, the defunct version in Stream2 is now stranded and the newly added appears with a member status. The stranded file will appear when you search for stranded elements.
If you try and promote the newly added foo.c, it will fail due to being an evil twin as the original foo.c still exists in Stream1.
To clear this, you can promote the stranded foo.c from Stream2 and then promote the newly added foo.c.
We have a need to refactor a code base. The thing is that this will be done by one person and it would be desirable to avoid having the rest of the development team sitting idle while this job takes place.
We therefore tried the following scenario to see if it is possible to work in parallel.
Created file test.txt in directory first in developer A's workspace.
Promoted this file.
Updated developer B's workspace, thereby getting file test.txt
In A's workspace moved file test.txt to directory second.
Promoted this move.
In B's workspace edited file test.txt while it still resides in directory first (no update is made thereby emulating that work is done while refactoring is taking place).
Tried to promote and got a message saying that file test.txt had been modified (correct, file has been moved).
Tried to merge but got an error message saying that AccuRev can't merge since the file is missing in directory second (where it has been moved).
Tried to update B's workspace but that is not allowed since there is a modified file that needs to be merged first.
We are now stuck in a catch 22 situation.
We did try to place a fake file in directory second but that is not being recognized since this file does not belong to the workspace.
Has anyone out there tried something like this and gotten it to work?
It is of course possible to copy files but if there is a better way we would be grateful to hear about this. Or if this is a known bug or limitation in the tool.
We will contact also contact AccuRev support but I thought that I might be able to get some useful tips from the community.
Currently we are using AccuRev client 5.5.0.
Thanks for any suggestions on how to make the tool support this operation.
Referring to your steps 6 & 7: In AccuRev 5.5 after a file is edited and has a (modified) status you first have to keep before you can promote.
At step 8 you could try doing the merge from the Browse Versions view of the file. That way you can select any node to merge with, including the one that has been moved.
Step 9. An AccuRev update will not run successfully if one of the files to be updated is (modified). This is by design. You can keep the file so it has (kept)(member) status then run the update.
David Howland
After contact with AccuRev support the answer is that the only option available is to copy the file to some temp directory, revert the changes, update the workspace and copy the file into the new location in the workspace.
AccuRev will at least tell you which files you have to copy since they will be marked as modified.
I could experimentally verify David's remark to step 9 using AccuRev 5.5.
Let's assume that in the workspace of user A the file was moved and the move was promoted, while in the workspace of user B the file was modified and user B is about to promote his/her change.
Before the file is kept, it will not be possible for user B neither to merge nor to update. But after keeping the modified file the update is possible. The file is first marked as overlap, then the merge succeeds in the new location. Basically, this avoids creating a copy of the file, reverting it and restoring it in the new location after an update, which can be quite cumbersome, as AccuRev does not reveal easily where the move goes.
If user B promotes the modification before user A promotes the move, all goes smoothly, i.e. on update the moved file appears as overlap, but easily merges into the moved file in the new location.
Similar results are obtained when the two users have workspaces connected to different streams and the overlap occurs on a common parent stream. Only if the file is unkept, an error can occur (i.e. only if the move is promoted before the change). Then a simple keep allows to proceed as usual (update, merge, then promote).