True, but it's possible for other queries to not touch the datastore as
well. Would be interesting to try to break it and see what happens.
Unplug a disk to see if neo still responds to read queries that are still
in the cache. :)
And yeah you're right, ::1 doesn't work in the config file (which is odd),
but if you bind to :: you can connect to ::1. Just tested with my go driver
using the following connection string:
db, err := sql.Open("neo4j-cypher", "http://[::1]:7474/";)
Wes
On Wed, Dec 18, 2013 at 1:22 PM, Alan Robertson <[email protected]> wrote:
> I meant to say "::1". Right now, it won't hear local only ipv6
> connections...
>
> But your suggested query doesn't have to touch the data store at all.
> Right?
>
> I would assume that either of the others I gave would touch the data
> store, and would typically fail of the data store was hung or broken...
>
> I would assume your suggested query would not touch the data store.
>
> Is that a correct understanding?
>
>
>
>
> On 12/18/2013 11:13 AM, Wes Freeman wrote:
>
> You can make it listen on :: if you set it in neo4j-server.properties:
> # Let the webserver only listen on the specified IP. Default is localhost
> (only
> # accept local connections). Uncomment to allow any connection. Please see
> the
> # security section in the neo4j manual before modifying this.
> org.neo4j.server.webserver.address=::
>
> My favorite ultra-simple 2.0 query is "RETURN 1;"--which works even if
> db is totally empty.
>
> Wes
>
> On Wed, Dec 18, 2013 at 10:56 AM, Alan Robertson <[email protected]> wrote:
>
>> 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]>
>> <[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]> <[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]> <[email protected]> - @OSSAlanR
>>
>> "Openness is the foundation and preservative of friendship... Let me claim
>> from you at all times your undisguised opinions." - William Wilberforce
>>
>>
>
>
> --
> Alan Robertson <[email protected]> <[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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