[jira] [Issue Comment Deleted] (CASSANDRA-6648) Race condition during node bootstrapping

["Ryan McGuire (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CASSANDRA-6648?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ryan McGuire updated CASSANDRA-6648:
------------------------------------

    Comment: was deleted

(was: Test case for when there's a patch: 

{code}
# Bring up test cluster:
ccm create bootstrap_bug
ccm populate -n 3
ccm start
ccm node1 stress -n 10000

# Bootstrap a new node:
ccm add -b node4 -t 127.0.0.4:9160 -l 127.0.0.4:7000 -j 7400 --binary-itf 127.0.0.4:9042
ccm node4 start

# Query data from the new node:
ccm node4 cqlsh

cqlsh>  select * from "Keyspace1"."Standard1" limit 10;
Bad Request: Keyspace Keyspace1 does not exist
{code})

> Race condition during node bootstrapping
> ----------------------------------------
>
>                 Key: CASSANDRA-6648
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-6648
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>            Reporter: Sergio Bossa
>            Assignee: Sergio Bossa
>            Priority: Critical
>         Attachments: 6648-v2.txt, 6648-v3.txt, CASSANDRA-6648.patch
>
>
> When bootstrapping a new node, data is "missing" as if the new node didn't actually bootstrap, which I tracked down to the following scenario:
> 1) New node joins token ring and waits for schema to be settled before actually bootstrapping.
> 2) The schema scheck somewhat passes and it starts bootstrapping.
> 3) Bootstrapping doesn't find the ks/cf that should have received from the other node.
> 4) Queries at this point cause NPEs, until when later they "recover" but data is missed.
> The problem seems to be caused by a race condition between the migration manager and the bootstrapper, with the former running after the latter.
> I think this is supposed to protect against such scenarios:
> {noformat}
>             while (!MigrationManager.isReadyForBootstrap())
>             {
>                 setMode(Mode.JOINING, "waiting for schema information to complete", true);
>                 Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
>             }
> {noformat}
> But MigrationManager.isReadyForBootstrap() implementation is quite fragile and doesn't take into account "slow" schema propagation.



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