accumulo-notifications mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Josh Elser (JIRA)" <>
Subject [jira] [Updated] (ACCUMULO-3174) Avoid mutation copy on remote replica
Date Sun, 05 Apr 2015 05:01:34 GMT


Josh Elser updated ACCUMULO-3174:
    Fix Version/s:     (was: 1.7.0)

> Avoid mutation copy on remote replica
> -------------------------------------
>                 Key: ACCUMULO-3174
>                 URL:
>             Project: Accumulo
>          Issue Type: Improvement
>          Components: replication
>            Reporter: Josh Elser
> To ensure that all replicas see mutations applied in the same order as the source, we
need to preserve the timestamp on the received mutations to replicate (either user-assigned
or server-assigned).
> The way that ServerMutation implements the server-assigned timestamp is done so as to
not modify the serialized bytes (for efficiencies sake). The problem arises when the ServerMutation
is cast back to a "regular" Mutation, the timestamp that the system assigned, which was tracked
outside of the serialized bytes, is lost and a new server-assigned timestamp is used.
> The naive way to circumvent this is to copy the ServerMutation into a new Mutation, checking
for a system-assigned timestamp and set that on the updates for each Mutation. This has a
big downside as the amount of required heap nearly doubled (assuming that the mutations are
the majority of memory used).

This message was sent by Atlassian JIRA

View raw message