Serialization failure on tariff publication

[jecollins]

Here's what I see in the server log when the default tariffs get published (at the 6-hour mark):

2011-05-08 21:05:46,389 [quartzScheduler_Worker-5] INFO tariffmarket.TariffMarketService - publishing 2 new tariffs
[org.powertac.common.Tariff : 1, org.powertac.common.Tariff : 2]
[org.powertac.common.Tariff : 1, org.powertac.common.Tariff : 2]
2011-05-08 21:05:46,427 [quartzScheduler_Worker-5] INFO core.JobRunShell - Job GRAILS_JOBS.org.powertac.common.ClockDriveJob threw a Job
ExecutionException:
org.quartz.JobExecutionException: Explicit selected converter cannot handle item
---- Debugging information ----
item-type : org.powertac.common.Broker_$$javassist_64
converter-type : com.thoughtworks.xstream.converters.SingleValueConverterWrapper
------------------------------- [See nested exception: com.thoughtworks.xstream.converters.ConversionException: Explicit selected converte
r cannot handle item
---- Debugging information ----
item-type : org.powertac.common.Broker$$javassist_64
converter-type : com.thoughtworks.xstream.converters.SingleValueConverterWrapper
-------------------------------]
at org.codehaus.groovy.grails.plugins.quartz.GrailsJobFactory$GrailsTaskClassJob.execute(GrailsJobFactory.java:81)
at org.quartz.core.JobRunShell.run(JobRunShell.java:199)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:546)
Caused by: com.thoughtworks.xstream.converters.ConversionException: Explicit selected converter cannot handle item
---- Debugging information ----
item-type : org.powertac.common.Broker$$_javassist_64

converter-type : com.thoughtworks.xstream.converters.SingleValueConverterWrapper

    at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:71)

...
at com.thoughtworks.xstream.XStream.toXML(XStream.java:789)
at com.thoughtworks.xstream.XStream$toXML.call(Unknown Source)
at org.powertac.common.MessageConverter.toXML(MessageConverter.groovy:55)
at org.powertac.common.MessageConverter$toXML.call(Unknown Source)
at org.powertac.server.BrokerProxyService.broadcastMessage(BrokerProxyService.groovy:79)
at org.powertac.common.interfaces.BrokerProxy$broadcastMessage.callCurrent(Unknown Source)
at org.powertac.server.BrokerProxyService.broadcastMessages(BrokerProxyService.groovy:104)
...
at org.powertac.tariffmarket.TariffMarketService.activate(TariffMarketService.groovy:276)
...

[jecollins]

This is because MessageConverter is written as a service, but packaged as a simple groovy class.

[jecollins]

No, it was because our serializer was not handling hibernate proxies correctly. Nguyen has fixed this by moving to a newer version of XStream and adding special handling of the proxies.