[jira] [Updated] (SPARK-1962) Add RDD cache reference counting
[
https://issues.apache.org/jira/browse/SPARK-1962?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Taeyun Kim updated SPARK-1962:
--
Description:
It would be nice if the RDD cache() method incorporate a reference counting
information.
That is,
{code}
void test()
{
JavaRDD... rdd = ...;
rdd.cache(); // to depth 1. actual caching happens.
rdd.cache(); // to depth 2. Nop as long as the storage level is the same.
Else, exception.
...
rdd.uncache(); // to depth 1. Nop.
rdd.uncache(); // to depth 0. Actual unpersist happens.
}
{code}
This can be useful when writing code in modular way.
When a function receives an rdd as an argument, it doesn't necessarily know the
cache status of the rdd.
But it could want to cache the rdd, since it will use the rdd multiple times.
But with the current RDD API, it cannot determine whether it should unpersist
it or leave it alone (so that caller can continue to use that rdd without
rebuilding).
Add RDD cache reference counting
Key: SPARK-1962
URL: https://issues.apache.org/jira/browse/SPARK-1962
Project: Spark
Issue Type: New Feature
Reporter: Taeyun Kim
Priority: Minor
It would be nice if the RDD cache() method incorporate a reference counting
information.
That is,
{code}
void test()
{
JavaRDD... rdd = ...;
rdd.cache(); // to depth 1. actual caching happens.
rdd.cache(); // to depth 2. Nop as long as the storage level is the same.
Else, exception.
...
rdd.uncache(); // to depth 1. Nop.
rdd.uncache(); // to depth 0. Actual unpersist happens.
}
{code}
This can be useful when writing code in modular way.
When a function receives an rdd as an argument, it doesn't necessarily know
the cache status of the rdd.
But it could want to cache the rdd, since it will use the rdd multiple times.
But with the current RDD API, it cannot determine whether it should unpersist
it or leave it alone (so that caller can continue to use that rdd without
rebuilding).
--
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[jira] [Updated] (SPARK-1962) Add RDD cache reference counting
[
https://issues.apache.org/jira/browse/SPARK-1962?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Taeyun Kim updated SPARK-1962:
--
Affects Version/s: 1.0.0
Add RDD cache reference counting
Key: SPARK-1962
URL: https://issues.apache.org/jira/browse/SPARK-1962
Project: Spark
Issue Type: New Feature
Affects Versions: 1.0.0
Reporter: Taeyun Kim
Priority: Minor
It would be nice if the RDD cache() method incorporate a reference counting
information.
That is,
{code}
void test()
{
JavaRDD... rdd = ...;
rdd.cache(); // to reference count 1. actual caching happens.
rdd.cache(); // to reference count 2. Nop as long as the storage level
is the same. Else, exception.
...
rdd.uncache(); // to reference count 1. Nop.
rdd.uncache(); // to reference count 0. Actual unpersist happens.
}
{code}
This can be useful when writing code in modular way.
When a function receives an RDD as an argument, it doesn't necessarily know
the cache status of the RDD.
But it could want to cache the RDD, since it will use the RDD multiple times.
But with the current RDD API, it cannot determine whether it should unpersist
it or leave it alone (so that the caller can continue to use that RDD without
rebuilding).
For API compatibility, introducing a new method or adding a parameter may be
required.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
[jira] [Updated] (SPARK-1962) Add RDD cache reference counting
[
https://issues.apache.org/jira/browse/SPARK-1962?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Patrick Wendell updated SPARK-1962:
---
Component/s: Spark Core
Add RDD cache reference counting
Key: SPARK-1962
URL: https://issues.apache.org/jira/browse/SPARK-1962
Project: Spark
Issue Type: New Feature
Components: Spark Core
Affects Versions: 1.0.0
Reporter: Taeyun Kim
Priority: Minor
It would be nice if the RDD cache() method incorporate a reference counting
information.
That is,
{code}
void test()
{
JavaRDD... rdd = ...;
rdd.cache(); // to reference count 1. actual caching happens.
rdd.cache(); // to reference count 2. Nop as long as the storage level
is the same. Else, exception.
...
rdd.uncache(); // to reference count 1. Nop.
rdd.uncache(); // to reference count 0. Actual unpersist happens.
}
{code}
This can be useful when writing code in modular way.
When a function receives an RDD as an argument, it doesn't necessarily know
the cache status of the RDD.
But it could want to cache the RDD, since it will use the RDD multiple times.
But with the current RDD API, it cannot determine whether it should unpersist
it or leave it alone (so that the caller can continue to use that RDD without
rebuilding).
For API compatibility, introducing a new method or adding a parameter may be
required.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
