(My continuing mission to explore new databases, to seek out strange 
bugs, to... never mind).

Ok, the next thing I'm interested in is reliablity.  IIUC, Magma 
doesn't have a transaction log, which means that reliability is 
definitely a worry: is it possible for me to corrupt the database?  How 
easy is it to lose data?

I'm starting a new session, and I'm going to leave it in a loop 
committing the current time as quickly as it can:

[[mySession commit: [mySession root at: 'now' put: Time now]] repeat] 
fork

Actually this is interesting - what happens when I try to read that 
time, while the commit loop is running?  Create a new session, try to 
access that key:

mySession2 root at: 'now'

Hmm, back to the silent-failure issue from part II.

Create a third session, same problem.

Well, hm, what do I do now?  I guess I can halt the ever-committing 
process and see what happens then.

Open the ProcessBrowser to try to kill the process (next time, keep a 
reference to it in the workspace), and the only one that seems right is 
currently in UndefinedObject>>handleSignal:.  Maybe we hit an error 
while trying to commit?  Try to debug the process, my image hangs.  Ok, 
trash that one.

New client image, open a new session, which seems to work - the server 
survived.  That's good.  But there's nothing at 'now' in the root.  Did 
*none* of those commits work?

Let's try that again with a delay between commits.

[[mySession commit: [(Delay forSeconds: 1) wait.  mySession root at: 
'now' put: Time now]] repeat] fork

Same problem: trying to access 'now' doesn't work.
Well, maybe I've screwed up the root object somehow.  Doesn't seem to 
be a way to reset the root, so I'll start a new repository on the 
server.

Start a new repository, start a server console going, try to repeat the 
test, hit the exact same issue.  I wonder - are there issues with 
having concurrent client sessions in different threads?  Instead of 
forking, let's try repeating this commit some finite number of times...

1000 timesRepeat: [mySession commit: [mySession root at: 'now' put: 
Time now]]

Ok, now try to access it:

mySession2 root at: 'now'

Oops, same problem.  Create a new session?

mySession3 root at: 'now'

Ok, that worked.

Now, let's try killing the server while that repeating commit is going 
on.

1000 timesRepeat: [mySession commit: [mySession root at: 'now' put: 
Time now]]

First gently: I'm saving and quitting the server image.  Some notifiers 
popped up about SharedQueue not being empty, but the image quit anyway.

Just out of curiosity, try to use the client session while the server 
is down.  My image locks up.  After a while, I manage to interrupt it, 
inside a critical section in MaTcpRequestServerLink>>submit:.

Ok, I bring the server image back up, close the notifiers, and start 
the console going again.

Try to connect from the client, but it locks again.  Do I need to 
manually signal that semaphore?

Try that, but still can't connect.  Let's switch to a new client image 
too.

Ok, that took quite a while, but it did connect.  Try to inspect the 
root, but all I get is the silent-failure thing again.

If I look back at the server image, I've got an MNU for UndefinedObject 
of
#maRead: bytes:bytesFromPosition:of:atFilePosition: .  Looks like the 
file is nil?  But it does exist:

Saba:~/Documents/Squeak/magma avi$ ls -l
total 192
-rw-r--r--  1 avi  staff  44592  9 Jul 12:40 myrepos.magma
-rw-r--r--  1 avi  staff  53184  9 Jul 14:21 myrepos2.magma

Hm... maybe starting up the server console on restart was a bad idea, 
maybe it does that for me and I should leave it alone.  Quit the server 
image, start it up again.  Use a fresh client image too.

Nope, same problem.  Maybe I hosed the server image by saving and 
quitting it?  I'll try a brand new server image and use the same 
database file.

Ok, that seems to work, and I get the root back ok.  Lesson learned: do 
not save and quit a running magma server.

Next question - what happens if I kill the process instead?  Start the 
repeating commit going, then force quit the server.
Start up a new server image.  Trying to connect from the old client 
image hangs; start a new client image too.

Ok, can connect, but can't get the root - same old strange 
silent-failure business.  Now I'm really stuck - this is a fresh server 
image and a fresh client image, and all I've tried to do is connect and 
look at the root.  Is my data gone forever?

Well, I think that's about as far as I'm willing to go today.  Frankly, 
it's a lot further than I would go if I were evaluating Magma for use, 
rather than trying to give as much feedback as possible - I hit enough 
issues along the way that I would have long since lost the ability to 
muster the 110% confidence I would need to entrust my data to it.  But 
I recognize that it's a work in progress, and so I hope my notes prove 
to be useful in taking it further.

Chris, if there are particular issues I found that you want help in 
reproducing, just let me know.

Cheers,
Avi