[GitHub] flink pull request #5521: [FLINK-8599] Improve the failure behavior of the F...
Github user StephanEwen commented on a diff in the pull request:
https://github.com/apache/flink/pull/5521#discussion_r173453379
--- Diff:
flink-streaming-java/src/main/java/org/apache/flink/streaming/api/functions/source/ContinuousFileReaderOperator.java
---
@@ -340,6 +341,10 @@ public void run() {
}
}
+ } catch (FileNotFoundException e) {
+ if (LOG.isDebugEnabled()) {
--- End diff --
This needs to be more prominently logged than `debug`. Should be at least
`info` or `warn`.
Please also use the placeholder syntax from log4j, to make the code simpler.
---
[GitHub] flink pull request #5521: [FLINK-8599] Improve the failure behavior of the F...
Github user StephanEwen commented on a diff in the pull request:
https://github.com/apache/flink/pull/5521#discussion_r173454031
--- Diff:
flink-core/src/main/java/org/apache/flink/api/common/io/FileInputFormat.java ---
@@ -819,6 +819,10 @@ public void open(FileInputSplit fileSplit) throws
IOException {
this.stream = isot.waitForCompletion();
this.stream = decorateInputStream(this.stream,
fileSplit);
}
+ catch (FileNotFoundException e) {
+ throw (FileNotFoundException)(new
FileNotFoundException("Input split " + fileSplit.getPath() +
--- End diff --
I don't understand why "skip and continue" is in this message.
Not all users of the `FileIputFormat` skip and continue. The interpretation
of the exception should not be assumed when creating the exception.
---
[GitHub] flink pull request #5521: [FLINK-8599] Improve the failure behavior of the F...
Github user steveloughran commented on a diff in the pull request:
https://github.com/apache/flink/pull/5521#discussion_r169604725
--- Diff:
flink-core/src/main/java/org/apache/flink/api/common/io/FileInputFormat.java ---
@@ -819,6 +819,10 @@ public void open(FileInputSplit fileSplit) throws
IOException {
this.stream = isot.waitForCompletion();
this.stream = decorateInputStream(this.stream,
fileSplit);
}
+ catch (FileNotFoundException e) {
+ throw new FileNotFoundException("Input split " +
fileSplit.getPath() +
+ " doesn't exist, skip and continue: "
+ e.getMessage());
+ }
--- End diff --
As this exception doesn't have a constructor which takes a nested
exception, can you use `initCause()` to patch it.
```java
throw (FileNotFoundException)(new FileNotFoundException(...)).initCause(e)
```
---
[GitHub] flink pull request #5521: [FLINK-8599] Improve the failure behavior of the F...
Github user steveloughran commented on a diff in the pull request:
https://github.com/apache/flink/pull/5521#discussion_r169275364
--- Diff:
flink-core/src/main/java/org/apache/flink/api/common/io/FileInputFormat.java ---
@@ -706,6 +700,9 @@ public void open(FileInputSplit fileSplit) throws
IOException {
this.stream = isot.waitForCompletion();
this.stream = decorateInputStream(this.stream,
fileSplit);
}
+ catch (FileNotFoundException e) {
+ throw new FileNotFoundException("Input split " +
fileSplit.getPath() + " doesn't exist, skip and continue");
+ }
--- End diff --
I would recommend including the text and stack of the caught ex, for the
better stack trace. FNFEs can get raised in odd circumstances in S3; seeing the
full stack is what you need when fielding support calls. eg.
```java
throw new FileNotFoundException("Input split " + fileSplit.getPath() + "
doesn't exist, skip and continue: " + e, e);
```
---
[GitHub] flink pull request #5521: [FLINK-8599] Improve the failure behavior of the F...
Github user steveloughran commented on a diff in the pull request:
https://github.com/apache/flink/pull/5521#discussion_r169132404
--- Diff:
flink-core/src/main/java/org/apache/flink/api/common/io/FileInputFormat.java ---
@@ -691,6 +691,12 @@ public void open(FileInputSplit fileSplit) throws
IOException {
LOG.debug("Opening input split " + fileSplit.getPath()
+ " [" + this.splitStart + "," + this.splitLength + "]");
}
+ if (!exists(fileSplit.getPath())) {
--- End diff --
you are doubling the number of checks for file existence here, which, when
working with S3 implies three more HTTP requests which takes time and cost
money. Better to do the open() call and catch FileNotFoundException, which all
filesystems are required to throw if they are given a path which doesn't
resolve to a file.
---
[GitHub] flink pull request #5521: [FLINK-8599] Improve the failure behavior of the F...
GitHub user ChengzhiZhao opened a pull request: https://github.com/apache/flink/pull/5521 [FLINK-8599] Improve the failure behavior of the FileInputFormat for ⦠## What is the purpose of the change This pull request is intent to improve the failure behavior of the ContinuousFileReader, currently if a bad file (for example, a different schema been dropped in this folder) came to the path and flink will do several retries. However, since the file path persist in the checkpoint, when people tried to resume from external checkpoint, it threw the following error on no file been found and the process cannot move forward. `java.io.IOException: Error opening the Input Split s3a://myfile [0,904]: No such file or directory: s3a://myfile` The change is to check if the path exist before open the file, if error occurs and bad file removed, flink should resume the process and continue. ## Brief change log - *Add a file exist check before open the file * ## Verifying this change - *Manually verified the change by introduce a bad file while continuously monitoring the folder, after remove the bad file, the process continued.* ## Does this pull request potentially affect one of the following parts: - Dependencies (does it add or upgrade a dependency): (no) - The public API, i.e., is any changed class annotated with `@Public(Evolving)`: (no) - The serializers: (no) - The runtime per-record code paths (performance sensitive): (no) - Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: (no) - The S3 file system connector: (no) ## Documentation - Does this pull request introduce a new feature? (no) - If yes, how is the feature documented? (not applicable) You can merge this pull request into a Git repository by running: $ git pull https://github.com/ChengzhiZhao/flink Improve_failure_behavior_FileInputFormat Alternatively you can review and apply these changes as the patch at: https://github.com/apache/flink/pull/5521.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #5521 commit 6fa8ef212c536acee56b2e9831ec92d1059449ff Author: Chengzhi Zhao Date: 2018-02-18T18:23:32Z [FLINK-8599] Improve the failure behavior of the FileInputFormat for bad files ---
