Thanks for the explanation.  I have always (mistakenly) thought of the
type of the relationship as a sort of property.

In any case, the script seems to work quite nicely, and is easy to
autogenerate the parameters for from Assimilation discovery information.

I discovered something surprising (a bug?) about curl -- unless I give
it the -g flag (don't expand globs), then it doesn't like ipv6 IP/port
combinations - like [::ffff:127.0.0.1]:7474.  IMHO, it shouldn't be
trying to glob IP addresses...

I noticed that neo4j doesn't appear to be ipv6 compliant (i.e., it
doesn't listen on '::').  Is that intentional?

In any case, the script seems to give neo4j some trivial, but meaningful
exercise.  You have to parse the query, optimize it, create a query
plan, execute it, walk through the results, convert them to JSON and
send them back out the REST interface.  Quite a few things have to be
working for it to succeed.

Do you have a favorite trivial query that will succeed in any non-empty
neo4j database?

Do you have a better grep pattern for matching correct output?


On 12/17/2013 11:18 PM, Michael Hunger wrote:
> return type(r)
>
> Empty curly braces mean no props
>
> Sent from mobile device
>
> Am 18.12.2013 um 06:41 schrieb Alan Robertson <[email protected]>:
>
>> The query in the script below produces the following output:
>> {"results":[{"columns":["one","rel","two"],"data":[{"row":[{"domain":"metadata","nodetype":"CMAclass","name":"HbRing"},{},{"domain":"metadata","nodetype":"CMAclass","name":"CMAclass"}]}]}],"errors":[]}
>>
>> What I noticed is that the relationship shows up as {}.  Do I need to
>> change the query to get the relationship type?  [See the script below
>> for the query]
>>
>> In any case, below is a script which does a passable job of seeing if
>> Neo4j is operational (and not dead, comatose, or laying on the ground
>> twitching)...  I'm going to write an OCF resource agent using it - so I
>> can monitor neo4j "properly".  And I could also make it highly-available
>> using Pacemaker...
>>
>> It can use either wget or curl to talk to Neo4j.
>>
>> #
>> #    Simple script to monitor Neo4j for basic operation
>> #
>> #    Potential inputs to this script are:
>> #    ipport:    IP-port combination of the neo4j REST server
>> #    cypher:    Cypher query string
>> #    regex:     Regular expression to match server output against
>> #    grepflags: flags to give grep
>> ipport='127.0.0.1:7474'
>> ipport='[::ffff:127.0.0.1]:7474'
>> cypher="START one=node(*) RETURN one LIMIT 1"
>> #    Need at least one node and one relationship for this one to succeed...
>> cypher="START one=node(*) MATCH one-[rel]->two RETURN one, rel, two LIMIT 1"
>> regex='^{ *"results" *: *\[.*\] *, *"errors" *: *\[ *\] *}$'
>> grepflags=""
>> #
>> #    Other variables in the script
>> #    queryjson:    JSON-encapsulated version of cypher query
>> #    committrans:  url suffix for committing transactions in one go
>> #    URL:          URL to give to Neo4j REST service
>> #    header:       Extra header information to give REST service (i.e.,
>> Content-type)
>> queryjson="{\"statements\" : [ { \"statement\" : \"$cypher\" } ] }"
>> committrans='db/data/transaction/commit'
>> URL=http://${ipport}/${committrans}
>> header='Content-type: application/json'
>> use_wget=1
>>
>> runquery() {
>>    if
>>      [ "$use_wget" -eq 1 ]
>>    then
>>      wget -q    --header="${header}" --post-data="$queryjson" 
>> --output-document=- $URL
>>    else
>>      curl -s -g --header "${header}" --data      "$queryjson"  --output
>> -          $URL
>>    fi
>> }
>> monitor() {
>>    runquery | grep ${grepflags} "${regex}" >/dev/null
>> }
>> runquery
>> monitor
>> rc=$?
>> echo $rc
>> exit $rc
>>
>>
>>
>> -- 
>>    Alan Robertson <[email protected]> - @OSSAlanR
>>
>> "Openness is the foundation and preservative of friendship...  Let me claim 
>> from you at all times your undisguised opinions." - William Wilberforce
>>
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-- 
    Alan Robertson <[email protected]> - @OSSAlanR

"Openness is the foundation and preservative of friendship...  Let me claim 
from you at all times your undisguised opinions." - William Wilberforce

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