[jira] [Updated] (CASSANDRA-7040) Replace read/write stage with per-disk access coordination
[ https://issues.apache.org/jira/browse/CASSANDRA-7040?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] C. Scott Andreas updated CASSANDRA-7040: Component/s: Local Write-Read Paths > Replace read/write stage with per-disk access coordination > -- > > Key: CASSANDRA-7040 > URL: https://issues.apache.org/jira/browse/CASSANDRA-7040 > Project: Cassandra > Issue Type: Improvement > Components: Local Write-Read Paths >Reporter: Benedict >Priority: Major > Labels: performance > Fix For: 4.x > > > As discussed in CASSANDRA-6995, current coordination of access to disk is > suboptimal: instead of ensuring disk accesses alone are coordinated, we > instead coordinate at the level of operations that may touch the disks, > ensuring only so many are proceeding at once. As such, tuning is difficult, > and we incur unnecessary delays for operations that would not touch the > disk(s). > Ideally we would instead simply use a shared coordination primitive to gate > access to the disk when we perform a rebuffer. This work would dovetail very > nicely with any work in CASSANDRA-5863, as we could prevent any blocking or > context switching for data that we know to be cached. It also, as far as I > can tell, obviates the need for CASSANDRA-5239. -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org
[jira] [Updated] (CASSANDRA-7040) Replace read/write stage with per-disk access coordination
[ https://issues.apache.org/jira/browse/CASSANDRA-7040?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Jonathan Ellis updated CASSANDRA-7040: -- Fix Version/s: (was: 3.0) 3.1 All right, let's move to 3.1 with 5863. > Replace read/write stage with per-disk access coordination > -- > > Key: CASSANDRA-7040 > URL: https://issues.apache.org/jira/browse/CASSANDRA-7040 > Project: Cassandra > Issue Type: Improvement > Components: Core >Reporter: Benedict > Labels: performance > Fix For: 3.1 > > > As discussed in CASSANDRA-6995, current coordination of access to disk is > suboptimal: instead of ensuring disk accesses alone are coordinated, we > instead coordinate at the level of operations that may touch the disks, > ensuring only so many are proceeding at once. As such, tuning is difficult, > and we incur unnecessary delays for operations that would not touch the > disk(s). > Ideally we would instead simply use a shared coordination primitive to gate > access to the disk when we perform a rebuffer. This work would dovetail very > nicely with any work in CASSANDRA-5863, as we could prevent any blocking or > context switching for data that we know to be cached. It also, as far as I > can tell, obviates the need for CASSANDRA-5239. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
