[
https://issues.apache.org/jira/browse/CASSANDRA-19009?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17795869#comment-17795869
]
David Capwell commented on CASSANDRA-19009:
-------------------------------------------
bq. The problem is that the requirement for TCM was to have full backwards
compatibility, so we still do apply schema mutations to the system_schema
keyspaces. Another problem is that by the time we are loading system_schema,
TCM is not yet initialised.
We can leave the new column for now and the downgrade work will need to deal
with it... I have not seen a clear plan for downgrade and we are far along in
5.0... so will see what happens there...
PR would be nice as I could comment at the code... trying to use
https://github.com/bdeggleston/cassandra/compare/128e704ec2500e37a0ee6847d151840976bcbb41..C19009-accord-fpconfig
* conf/cassandra.yaml
Shouldn't fast_path_update_delay be under the accord? Its in
src/java/org/apache/cassandra/config/AccordSpec.java, so its accord.
fast_path_update_delay
* src/java/org/apache/cassandra/service/accord/AccordFastPathCoordinator.java
isShutdown returns false if the local node isn't in AccordFastPath, so we won't
add ourselves as NORMAL?
Updated logic LGTM +1
> CEP-15: (C*/Accord) Schema based fast path reconfiguration
> -----------------------------------------------------------
>
> Key: CASSANDRA-19009
> URL: https://issues.apache.org/jira/browse/CASSANDRA-19009
> Project: Cassandra
> Issue Type: Improvement
> Components: Accord
> Reporter: Blake Eggleston
> Assignee: Blake Eggleston
> Priority: Normal
> Fix For: 5.0.x
>
>
> This adds availability aware accord fast path reconfiguration, as well as
> user configurable fast path settings, which are set at the keyspace level and
> (optionally) at the table level for increased granularity.
> The major parts are:
> *Add availability information to cluster metadata*
> Accord topology in C* is not stored in cluster metadata, but is meant to
> calculated deterministically from cluster metadata state at a given epoch.
> This adds the availability data, as well as the failure detector / gossip
> listener and state change deduplication to CMS.
> *Move C* accord keys/topology from keyspace prefixes to tableid prefixes*
> To support per-table fast path settings, topologies and keys need to include
> the table id. Since accord topologies could begin to consume a lot of memory
> in clusters with a lot of nodes and tables, topology generation has been
> updated to reuse previously allocated shards / shard parts where possible,
> which will only increase heap sizes when things actually change.
> *Make fast path settings configurable via schema*
> There are 2.5 strategies: Simple, Parameterized, and InheritKeyspaceSettings.
> Simple will use as many available nodes as possible for the fast path
> electorate, this is the default for the keyspace fast path strategy.
> Parameterized allows you to set a target size, and preferred datacenters for
> the FP electorate. InheritKeyspace tells topology generation to just use the
> keyspace fast path settings, and is the default for the table fast path
> strategy.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
