Scalaris 0.6.1 released

[Nico Kruber]

We are happy to announce the new bugfix release of Scalaris, 0.6.1. Some small
features also made it into the release but it is mainly focussed on stability
and performance improvements of some of the algorithms we use. Please refer to
the most notable changes, listed below.

As usually, the source can be downloaded from
https://code.google.com/p/scalaris/

Packages for various linux distributions are available in the Open Build
Service:
The latest stable version is available in our main repository:
http://download.opensuse.org/repositories/home:/scalaris/

If you would like to stick with the 0.6 branch, use this repository:
http://download.opensuse.org/repositories/home:/scalaris:/0.6.x/

Scalaris' Java-API (in different versions) is also available in our maven
repository at:
https://scalaris.googlecode.com/svn/maven/


Scalaris 0.6.1 - October 11, 2013
=================================

Packaging:

- add ArchLinux ruby API packages

API:

- Java-API: add Maven build support
- Java-API: add CircularByteArrayOutputStream#clear()
- Java-API: fix ConnectionPool#getConnection(timeout) throwing
IllegalMonitorStateException if a single ConnectionPool is used
by multiple threads and no more connections are available
- Java-API: add a "-monitor" command line parameter
- api_monitor: return the latency and stddev values of the micro-benchmark
executed by monitor_perf for node and service performance

Demonstrator "Wiki on Scalaris" (supported by 4CaaSt http://www.4caast.eu/
and Contrail http://contrail-project.eu):

- separate list counters from their list partitions for a better data layout
- fix high memory use of the Scalaris import if the import is slow
- use tomcat 7.0.42

Business Logic:

- rrepair: reduce overhead of ART reconciliation
- rrepair: allow resolving of multiple merkle node leaves with a single
resolve request
- rrepair: don't create resolve requests for empty intervals
- rrepair: reduce overhead of update_key_entry requests (use a single request
with all the data instead of one request for each item)
- rrepair: allow arbitrary intervals in interval_upd and interval_upd_send
resolve requests again
- rrepair: when hashing merkle_tree/ART children, also include the represented
interval (fixes indistinguishable empty leaf nodes in ART)
- tx_tm_rtm: re-enable takeover by rtms on tm crash
- rt_chord: only re-build the RT if the pred or succ processes change or the
own new node ID is not between the new pred and succ any more

Infrastructure:

- DB: improve performance of fold[lr] implementations by a factor of 2
- FD: get rid of annoying, wrongly raised log warnings
- RM: provide a more generic Reason for RM subscriptions
- RM: remove trigger infections
- RT: don't trigger an update when a slide finishes
- RT, FRT: reduce the number of messages sent on lookups
- log: don't exit with a badmatch if our error_logger is not the only one

Tests:

- add protocol scheduler tests for slide, join and leave

Documentation:

- user-dev-guide: add section on scalarisctl checkinstallation
- user-dev-guide: clarify the section about how to set up Scalaris

Tools:

- proto scheduler: continue in case of send errors
- top: improve process messages output

Bugs:

- node join: fix not being able to join a system with passive load balancer
if the number of items in the DB is too high
- tx_tm_rtm: fix wrong asserts
- fix node resposibility check not always including message forward and
db_range intervals
- tx_tp: add missing snapshot number in tp_do_commit_abort message
- bulkowner: respect the nodes' DB ranges and forward requests for
non-responsible ranges
- dn_cache: fix reporting wrong PIDs back as zombies after node reboots
- fix some more (less severe) bugs