Ühel kenal päeval, E, 2006-03-06 kell 18:08, kirjutas Christopher
Browne:
> There is a list of Works In Progress...
> 
> http://slony-wiki.dbitech.ca/index.php/Works_In_Progress
> 
> Most things are addressed, at this point.
> 
> We should see about making sure that outstanding items that should be
> done for 1.2 are assigned.
> 
> Once they are done, we should see about scheduling a release, which will
> need to include a goodly amount of testing, as there is a LOT of new
> stuff, including:
> 
> - Windows support
> - Major revision of memory management (so that big tuples don't blow
> memory out) which should limit memory usage pretty incredibly
> - DDL scripts are broken into individual statements
> - Log switching (between sl_log_1 and sl_log_2)
> - Subscribe set aggressively locks tables on the subscriber to avoid
> failures
> - A lot of fixes to build environment (this needs to be tested on lots
> of platforms)
> - pg_listener is used *way* less; slon uses polling, if things are
> running busily
> - slon "lag interval" option
> - slon "stop after event" option
> 
> I'd like to improve some of the scripts, probably via redoing watchdogs
> in plain shell; it's not clear if that'll happen for 1.2...
> 
> At any rate, if this list of enhancements is incomplete, I'd appreciate
> hearing about what may be missing.  And if there are things that Just
> Must Go In, we'd be best to know that ASAP...

I have'nt checked latest versions, but I fear that there are still some
footguns lurking in how subscribe is done, especially what is checked
and what not.

A) Last time I checked, it was still possible to redirect subscriber to
a node, where the subscribed table might even not exists.

example:
   I have nodea 1, 2 and three
   set1 has master on node 1 and subscriber on node2 
   it was possible to change subscribe of set1  on node2 to use node3 as
master, even though there was no set1 there - no error, no warning,
nothing.


B) Another thing:
  It seems that if there are no sub-subscribers on subscriber, then even
with "subscribe, forward=yes", nothing is stored in sl_log_1. when doing
a change in subscription from one node to another it is then possible to
lose some data

example:
   nodes 1,2,3,4
   subscribe set1 1 -> 2 -> 4 , and 1 -> 3 with forward
   no change 4 to use 3 as its source - some data is lost

C) And yet another maybe even more fundamental thing

paths are calculated based on nodes, but subscription unit is a set, so
subscribing some sets from 1 to 4 (above) via node 2 and some via node 3
does not work as events just do not propagate. It annoys most if you
have several sets subscribed 
1 -> 2 -> 4, and want to move the subscription to use 1 -> 3 -> 4.
Doing by changing subcription of sets on node4 to use node3 instead of
node2 either fails completely or just loses data.

Another confusing thing about this is, that subscribing of a new set
works through the COPY phase, and then fails, when events from sl_log_1
should start moving


A) and possibly B) should be asy to fix. I dont know how hard C) is 

-------------------
Hannu


























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