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I had one last idea for how to do this in a simpler way, and this time made sure the tests are actually working too. I realized that there's no benefit (that I can think of) to having one map from X to task set manager, and a second mapping from task id to X; we might as well just directly store a mapping from TaskId to task set manager. Let me know what you think.

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there is a change in behavior here. If you've got a zombie attempt with some tasks still running, but you also have a new active attempt, then when cancelTasks gets called, you'll only kill the tasks for the active attempt. The zombie attempt will not longer have its tasks cancelled.

I know this is a corner case, but it just means the behavior will be even more confusing when we do encounter it ...

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so one way around this would be if cancelled tasks as soon as an attempt was marked zombie (which we should probably do anyway, we have several lingering TODOs for it). But, I'm thinking maybe we can save this for a future improvement?

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one more thought: one thing which kinda bugs me now is that TaskSetManager.isZombie is just a var, so a potential bug is if somebody decides to set it back to true. Really it should be private and we have a markZombie() method or something, which would also be where we could create a request to cancel all of the tasks.

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Agree with all of the above, especially the bit about actually canceling tasks when an attempt is marked zombie, because it's so easy to do.

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(and fine to save this for a future cleanup)

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also realizing this is yet another untested part of TaskSchedulerImpl ...

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squito commented Jul 17, 2015

@kayousterhout I like the code cleanup of this change, but I think we might be stuck b/c of cancelTasks.

I do like the change from

val taskIdToStageIdAndAttempt = new HashMap[Long, (Int, Int)]

to

val taskIdToTaskSet = new HashMap[Long, TaskSetManager]

at least, though I know you were hoping for a bigger cleanup.

squito pushed a commit that referenced this pull request Apr 13, 2016
…l` in IF/CASEWHEN

## What changes were proposed in this pull request?

Currently, `SimplifyConditionals` handles `true` and `false` to optimize branches. This PR improves `SimplifyConditionals` to take advantage of `null` conditions for `if` and `CaseWhen` expressions, too.

**Before**
```
scala> sql("SELECT IF(null, 1, 0)").explain()
== Physical Plan ==
WholeStageCodegen
:  +- Project [if (null) 1 else 0 AS (IF(CAST(NULL AS BOOLEAN), 1, 0))#4]
:     +- INPUT
+- Scan OneRowRelation[]
scala> sql("select case when cast(null as boolean) then 1 else 2 end").explain()
== Physical Plan ==
WholeStageCodegen
:  +- Project [CASE WHEN null THEN 1 ELSE 2 END AS CASE WHEN CAST(NULL AS BOOLEAN) THEN 1 ELSE 2 END#14]
:     +- INPUT
+- Scan OneRowRelation[]
```

**After**
```
scala> sql("SELECT IF(null, 1, 0)").explain()
== Physical Plan ==
WholeStageCodegen
:  +- Project [0 AS (IF(CAST(NULL AS BOOLEAN), 1, 0))#4]
:     +- INPUT
+- Scan OneRowRelation[]
scala> sql("select case when cast(null as boolean) then 1 else 2 end").explain()
== Physical Plan ==
WholeStageCodegen
:  +- Project [2 AS CASE WHEN CAST(NULL AS BOOLEAN) THEN 1 ELSE 2 END#4]
:     +- INPUT
+- Scan OneRowRelation[]
```

**Hive**
```
hive> select if(null,1,2);
OK
2
hive> select case when cast(null as boolean) then 1 else 2 end;
OK
2
```

## How was this patch tested?

Pass the Jenkins tests (including new extended test cases).

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes apache#12122 from dongjoon-hyun/SPARK-14338.
squito pushed a commit that referenced this pull request Sep 5, 2017
…pressions

## What changes were proposed in this pull request?

This PR changes the direction of expression transformation in the DecimalPrecision rule. Previously, the expressions were transformed down, which led to incorrect result types when decimal expressions had other decimal expressions as their operands. The root cause of this issue was in visiting outer nodes before their children. Consider the example below:

```
    val inputSchema = StructType(StructField("col", DecimalType(26, 6)) :: Nil)
    val sc = spark.sparkContext
    val rdd = sc.parallelize(1 to 2).map(_ => Row(BigDecimal(12)))
    val df = spark.createDataFrame(rdd, inputSchema)

    // Works correctly since no nested decimal expression is involved
    // Expected result type: (26, 6) * (26, 6) = (38, 12)
    df.select($"col" * $"col").explain(true)
    df.select($"col" * $"col").printSchema()

    // Gives a wrong result since there is a nested decimal expression that should be visited first
    // Expected result type: ((26, 6) * (26, 6)) * (26, 6) = (38, 12) * (26, 6) = (38, 18)
    df.select($"col" * $"col" * $"col").explain(true)
    df.select($"col" * $"col" * $"col").printSchema()
```

The example above gives the following output:

```
// Correct result without sub-expressions
== Parsed Logical Plan ==
'Project [('col * 'col) AS (col * col)#4]
+- LogicalRDD [col#1]

== Analyzed Logical Plan ==
(col * col): decimal(38,12)
Project [CheckOverflow((promote_precision(cast(col#1 as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) AS (col * col)#4]
+- LogicalRDD [col#1]

== Optimized Logical Plan ==
Project [CheckOverflow((col#1 * col#1), DecimalType(38,12)) AS (col * col)#4]
+- LogicalRDD [col#1]

== Physical Plan ==
*Project [CheckOverflow((col#1 * col#1), DecimalType(38,12)) AS (col * col)#4]
+- Scan ExistingRDD[col#1]

// Schema
root
 |-- (col * col): decimal(38,12) (nullable = true)

// Incorrect result with sub-expressions
== Parsed Logical Plan ==
'Project [(('col * 'col) * 'col) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Analyzed Logical Plan ==
((col * col) * col): decimal(38,12)
Project [CheckOverflow((promote_precision(cast(CheckOverflow((promote_precision(cast(col#1 as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Optimized Logical Plan ==
Project [CheckOverflow((cast(CheckOverflow((col#1 * col#1), DecimalType(38,12)) as decimal(26,6)) * col#1), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Physical Plan ==
*Project [CheckOverflow((cast(CheckOverflow((col#1 * col#1), DecimalType(38,12)) as decimal(26,6)) * col#1), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- Scan ExistingRDD[col#1]

// Schema
root
 |-- ((col * col) * col): decimal(38,12) (nullable = true)
```

## How was this patch tested?

This PR was tested with available unit tests. Moreover, there are tests to cover previously failing scenarios.

Author: aokolnychyi <anton.okolnychyi@sap.com>

Closes apache#18583 from aokolnychyi/spark-21332.
squito pushed a commit that referenced this pull request Sep 21, 2017
…pressions

## What changes were proposed in this pull request?

This PR changes the direction of expression transformation in the DecimalPrecision rule. Previously, the expressions were transformed down, which led to incorrect result types when decimal expressions had other decimal expressions as their operands. The root cause of this issue was in visiting outer nodes before their children. Consider the example below:

```
    val inputSchema = StructType(StructField("col", DecimalType(26, 6)) :: Nil)
    val sc = spark.sparkContext
    val rdd = sc.parallelize(1 to 2).map(_ => Row(BigDecimal(12)))
    val df = spark.createDataFrame(rdd, inputSchema)

    // Works correctly since no nested decimal expression is involved
    // Expected result type: (26, 6) * (26, 6) = (38, 12)
    df.select($"col" * $"col").explain(true)
    df.select($"col" * $"col").printSchema()

    // Gives a wrong result since there is a nested decimal expression that should be visited first
    // Expected result type: ((26, 6) * (26, 6)) * (26, 6) = (38, 12) * (26, 6) = (38, 18)
    df.select($"col" * $"col" * $"col").explain(true)
    df.select($"col" * $"col" * $"col").printSchema()
```

The example above gives the following output:

```
// Correct result without sub-expressions
== Parsed Logical Plan ==
'Project [('col * 'col) AS (col * col)#4]
+- LogicalRDD [col#1]

== Analyzed Logical Plan ==
(col * col): decimal(38,12)
Project [CheckOverflow((promote_precision(cast(col#1 as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) AS (col * col)#4]
+- LogicalRDD [col#1]

== Optimized Logical Plan ==
Project [CheckOverflow((col#1 * col#1), DecimalType(38,12)) AS (col * col)#4]
+- LogicalRDD [col#1]

== Physical Plan ==
*Project [CheckOverflow((col#1 * col#1), DecimalType(38,12)) AS (col * col)#4]
+- Scan ExistingRDD[col#1]

// Schema
root
 |-- (col * col): decimal(38,12) (nullable = true)

// Incorrect result with sub-expressions
== Parsed Logical Plan ==
'Project [(('col * 'col) * 'col) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Analyzed Logical Plan ==
((col * col) * col): decimal(38,12)
Project [CheckOverflow((promote_precision(cast(CheckOverflow((promote_precision(cast(col#1 as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Optimized Logical Plan ==
Project [CheckOverflow((cast(CheckOverflow((col#1 * col#1), DecimalType(38,12)) as decimal(26,6)) * col#1), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Physical Plan ==
*Project [CheckOverflow((cast(CheckOverflow((col#1 * col#1), DecimalType(38,12)) as decimal(26,6)) * col#1), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- Scan ExistingRDD[col#1]

// Schema
root
 |-- ((col * col) * col): decimal(38,12) (nullable = true)
```

## How was this patch tested?

This PR was tested with available unit tests. Moreover, there are tests to cover previously failing scenarios.

Author: aokolnychyi <anton.okolnychyi@sap.com>

Closes apache#18583 from aokolnychyi/spark-21332.

(cherry picked from commit 0be5fb4)
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
squito pushed a commit that referenced this pull request May 18, 2018
…pressions

## What changes were proposed in this pull request?

This PR changes the direction of expression transformation in the DecimalPrecision rule. Previously, the expressions were transformed down, which led to incorrect result types when decimal expressions had other decimal expressions as their operands. The root cause of this issue was in visiting outer nodes before their children. Consider the example below:

```
    val inputSchema = StructType(StructField("col", DecimalType(26, 6)) :: Nil)
    val sc = spark.sparkContext
    val rdd = sc.parallelize(1 to 2).map(_ => Row(BigDecimal(12)))
    val df = spark.createDataFrame(rdd, inputSchema)

    // Works correctly since no nested decimal expression is involved
    // Expected result type: (26, 6) * (26, 6) = (38, 12)
    df.select($"col" * $"col").explain(true)
    df.select($"col" * $"col").printSchema()

    // Gives a wrong result since there is a nested decimal expression that should be visited first
    // Expected result type: ((26, 6) * (26, 6)) * (26, 6) = (38, 12) * (26, 6) = (38, 18)
    df.select($"col" * $"col" * $"col").explain(true)
    df.select($"col" * $"col" * $"col").printSchema()
```

The example above gives the following output:

```
// Correct result without sub-expressions
== Parsed Logical Plan ==
'Project [('col * 'col) AS (col * col)#4]
+- LogicalRDD [col#1]

== Analyzed Logical Plan ==
(col * col): decimal(38,12)
Project [CheckOverflow((promote_precision(cast(col#1 as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) AS (col * col)#4]
+- LogicalRDD [col#1]

== Optimized Logical Plan ==
Project [CheckOverflow((col#1 * col#1), DecimalType(38,12)) AS (col * col)#4]
+- LogicalRDD [col#1]

== Physical Plan ==
*Project [CheckOverflow((col#1 * col#1), DecimalType(38,12)) AS (col * col)#4]
+- Scan ExistingRDD[col#1]

// Schema
root
 |-- (col * col): decimal(38,12) (nullable = true)

// Incorrect result with sub-expressions
== Parsed Logical Plan ==
'Project [(('col * 'col) * 'col) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Analyzed Logical Plan ==
((col * col) * col): decimal(38,12)
Project [CheckOverflow((promote_precision(cast(CheckOverflow((promote_precision(cast(col#1 as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) as decimal(26,6))) * promote_precision(cast(col#1 as decimal(26,6)))), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Optimized Logical Plan ==
Project [CheckOverflow((cast(CheckOverflow((col#1 * col#1), DecimalType(38,12)) as decimal(26,6)) * col#1), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- LogicalRDD [col#1]

== Physical Plan ==
*Project [CheckOverflow((cast(CheckOverflow((col#1 * col#1), DecimalType(38,12)) as decimal(26,6)) * col#1), DecimalType(38,12)) AS ((col * col) * col)apache#11]
+- Scan ExistingRDD[col#1]

// Schema
root
 |-- ((col * col) * col): decimal(38,12) (nullable = true)
```

## How was this patch tested?

This PR was tested with available unit tests. Moreover, there are tests to cover previously failing scenarios.

Author: aokolnychyi <anton.okolnychyi@sap.com>

Closes apache#18583 from aokolnychyi/spark-21332.

(cherry picked from commit 0be5fb4)
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
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