On 3/11/2016 10:21 PM, Brian Wright wrote:
> Use the |SOLR_HOST|variable in the include file to set the hostname of
> the Solr server.
> |SOLR_HOST=solr1.example.com|
>
> Setting the hostname of the Solr server is recommended, especially
> when running in SolrCloud mode, as this determines the address of the
> node when it registers with ZooKeeper.
>
>
> Yet, in the example solr.xml, the <solrcloud> stanza defines ...
>
> <solrcloud>
>
> <str name="host">${host:}</str>
> <int name="hostPort">${jetty.port:8983}</int>
> <str name="hostContext">${hostContext:solr}</str>
>
> <bool name="genericCoreNodeNames">${genericCoreNodeNames:true}</bool>
>
> <int name="zkClientTimeout">${zkClientTimeout:30000}</int>
> <int
> name="distribUpdateSoTimeout">${distribUpdateSoTimeout:600000}</int>
> <int
> name="distribUpdateConnTimeout">${distribUpdateConnTimeout:60000}</int>
>
> </solrcloud>
>
>
> More specifically the ${host:} variable. When this variable is filled
> in from startup execution, Zookeeper seems to obtain the correct
> hostname in spite of SOLR_HOST having been set. Yet, the docs
> recommend setting (or additionally setting?) SOLR_HOST with an
> explicit hostname.
The SOLR_HOST environment variable is used by the startup shell script
(I looked at 5.4.0, the Windows start script has a command that
accomplishes the same thing) -- setting the Java system property named
"host":
SOLR_HOST_ARG=("-Dhost=$SOLR_HOST")
The solr.xml file contains ${host:} which tells it to use that java
property. The colon in the property name determines the value if the
property is not available -- blank in this case . A blank value for the
"host" setting in solr.xml means that Solr will use its default -- the
first IP address on the machine.
If SOLR_HOST is not working, perhaps the start script in your install
has a bug. I was going to look for reported bugs on SOLR_HOST, but the
Apache bugtracker (Jira) is down.
Thanks,
Shawn
