You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@cassandra.apache.org by jean paul <re...@gmail.com> on 2016/08/11 12:16:34 UTC
Question nodetool status
Hi all,
*$nodetool status*Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
-- Address Load Tokens Owns (effective) Host
ID Rack
*UN 127.0.0.1 83.05 KB 256 100.0%
460ddcd9-1ee8-48b8-a618-c076056aad07 rack1*
*The nodetool command* shows the status of the node (UN=up, DN=down):
Please i'd like to know how this command works and is it based on gossip
protocol or not ?
Thank you so much for explanations.
Best regards.
Re: Question nodetool status
Posted by Romain Hardouin <ro...@yahoo.fr>.
It's a bit more involved than that. C* uses a "Phi accrual failure detector":https://docs.datastax.com/en/cassandra/3.x/cassandra/architecture/archDataDistributeFailDetect.html
https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L878See also https://dspace.jaist.ac.jp/dspace/bitstream/10119/4784/1/IS-RR-2004-010.pdf
Best,
Romain
Le Jeudi 11 août 2016 17h02, jean paul <re...@gmail.com> a écrit :
Hi, thanks a lot for answer :)
Gossip is a peer-to-peer communication protocol in which nodes periodically exchange state information about themselves and about other nodes they know about.
unreachableNodes = probe.getUnreachableNodes(); ---> i.e if nodedon't publish heartbeats on x seconds (using gossip protocol), it's therefore marked 'DN: down' ?
That's it?
2016-08-11 13:51 GMT+01:00 Romain Hardouin <ro...@yahoo.fr>:
Hi Jean Paul,
Yes, the gossiper is used. Example with down nodes:1. The status command retrieve unreachable nodes from a NodeProbe instance: https://github.com/ apache/cassandra/blob/trunk/ src/java/org/apache/cassandra/ tools/nodetool/Status.java#L64
2. The NodeProbe list comes from a StorageService proxy: https://github.com/apache/ cassandra/blob/trunk/src/java/ org/apache/cassandra/tools/ NodeProbe.java#L4383. The proxy calls the Gossiper singleton: https://github.com/ apache/cassandra/blob/trunk/ src/java/org/apache/cassandra/ service/StorageService.java# L2681
Best,
Romain
Le Jeudi 11 août 2016 14h16, jean paul <re...@gmail.com> a écrit :
Hi all,
$nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/ Moving
-- Address Load Tokens Owns (effective) Host ID Rack
UN 127.0.0.1 83.05 KB 256 100.0% 460ddcd9-1ee8-48b8-a618- c076056aad07 rack1
The nodetool command shows the status of the node (UN=up,DN=down):
Please i'd like to know how this command works and is it based on gossip protocol or not ?
Thank you so much for explanations.Best regards.
Re: Question nodetool status
Posted by jean paul <re...@gmail.com>.
Hi, thanks a lot for answer :)
Gossip is a peer-to-peer communication protocol in which nodes periodically
exchange state information about themselves and about other nodes they know
about.
unreachableNodes = probe.getUnreachableNodes(); ---> i.e if node don't
publish heartbeats on x seconds (using gossip protocol), it's therefore
marked 'DN: down' ?
That's it?
2016-08-11 13:51 GMT+01:00 Romain Hardouin <ro...@yahoo.fr>:
> Hi Jean Paul,
>
> Yes, the gossiper is used. Example with down nodes:
> 1. The status command retrieve unreachable nodes from a NodeProbe
> instance: https://github.com/apache/cassandra/blob/trunk/
> src/java/org/apache/cassandra/tools/nodetool/Status.java#L64
> 2. The NodeProbe list comes from a StorageService proxy:
> https://github.com/apache/cassandra/blob/trunk/src/java/
> org/apache/cassandra/tools/NodeProbe.java#L438
> 3. The proxy calls the Gossiper singleton: https://github.com/
> apache/cassandra/blob/trunk/src/java/org/apache/cassandra/
> service/StorageService.java#L2681
>
> Best,
>
> Romain
>
> Le Jeudi 11 août 2016 14h16, jean paul <re...@gmail.com> a écrit :
>
>
> Hi all,
>
>
>
> *$nodetool status*Datacenter: datacenter1
> =======================
> Status=Up/Down
> |/ State=Normal/Leaving/Joining/ Moving
> -- Address Load Tokens Owns (effective) Host
> ID Rack
>
>
> *UN 127.0.0.1 83.05 KB 256 100.0%
> 460ddcd9-1ee8-48b8-a618- c076056aad07 rack1*
> *The nodetool command* shows the status of the node (UN=up, DN=down):
>
> Please i'd like to know how this command works and is it based on gossip
> protocol or not ?
>
> Thank you so much for explanations.
> Best regards.
>
>
>
>
>
Re: Question nodetool status
Posted by Romain Hardouin <ro...@yahoo.fr>.
Hi Jean Paul,
Yes, the gossiper is used. Example with down nodes:1. The status command retrieve unreachable nodes from a NodeProbe instance: https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/tools/nodetool/Status.java#L64
2. The NodeProbe list comes from a StorageService proxy: https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/tools/NodeProbe.java#L4383. The proxy calls the Gossiper singleton: https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/service/StorageService.java#L2681
Best,
Romain
Le Jeudi 11 août 2016 14h16, jean paul <re...@gmail.com> a écrit :
Hi all,
$nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/ Moving
-- Address Load Tokens Owns (effective) Host ID Rack
UN 127.0.0.1 83.05 KB 256 100.0% 460ddcd9-1ee8-48b8-a618- c076056aad07 rack1
The nodetool command shows the status of the node (UN=up,DN=down):
Please i'd like to know how this command works and is it based on gossip protocol or not ?
Thank you so much for explanations.Best regards.