Apache Camel GenericFileOperationFailedException: 'Cannot rename file' locks exchange - apache-camel

We have an integration system based on Camel v2.16.1 that runs on a Jboss v6 Linux platform. There are multiple interfaces running simultaneously each with a different polling rate.
We are intermittently experiencing 'Cannot rename file' issue with Camel failing to backup to the 'done' folder successfully processed and transmitted files from the FTP source. Restarting the camel application fixes the issue.
Basically, at regular intervals triggered by a quartz scheduler, the route:
picks up files from a source via FTP,
processes them, smooks + xsl transformations
delivers the generated flat file to an endpoint via FTP.
If multiple files are read from the source directory, then all the files are appended together in a temporary file before being processed.
The Camel FTP configuration uses the following URL:
ftp://xxxx/export?antInclude=dsciord_*.dat&inProgressRepository=#warehouseIntegrationIdempotentRepository&preMove=in_progress_bpo/$simple{date:now:yyyyMMddHHmm}/$simple{file:name}&move=done&consumer.bridgeErrorHandler=true
read files dsciord_*.dat from /export directory
use custom inprogressRepository to store the read filename into a local db (this was done to prevent contention issue with a second cluster node, however, currently only a single node is live. This option is unnecessary and can be removed speeding up the process).
move files to an in_progress_bpo/201609061522 directory, where the subdirectory is created based on the date_timestamp.
move them to the in_progress_bpo/201609061522/done subdirectory once successfully processed.
In vast majority of cases the route works with no issues, however, sometimes the file(s) cannot be moved to the done folder (see error below). Even in this case, the route can sometimes continue successfully at the next polling cycle, however, in other cases the route enters a state when even if the quartz scheduler triggers the poll, the route fails to detect any files in the source /export directory even when there ARE files there.
org.apache.camel.component.file.GenericFileOperationFailedException: Cannot rename file: RemoteFile[in_progress_bpo/201609060502/dsciord_3605752.dat] to: RemoteFile[in_progress_bpo/201609060502/done/dsciord_3605752.dat]
Notes: We are using
a single instance of a ConsumerTemplate to handle our interfaces.
a custom inprogressRepository to store the file names read.
Obviously, there must be a system locking the source files and this is causing the Camel route to stop processing further files.
Any ideas/suggestions on debugging/resolving this issue would be greatly appreciated. The issues that I read through the camel-users forum seem to deal with Windows-related deployments, sometimes Smooks failing to close the input stream. I've check and we don't use the
org.milyn.templating.xslt.XslTemplateProcessor#bypass method where Smooks fails to close the underlying input stream.

Finally I have been able to reproduce/identify the issue.
Given that we are using a relative path to move the processed files into once successfully ftp-ed to the destination servers:
../../../u/4gl_upload/warehouse_integration_2/trs-server/export/in_progress_bpo/201609081030/done
However, for some reason instead of traversing the via correct path to move the processed files the camel consumer creates a new subdirectory tree starting from the current working directory and this could be quite long as follows. Hence the problem. It doesn’t know where it is and it doesn’t reset itself.
/u/4gl_upload/warehouse_integration_2/trs-server/u/4gl_upload/warehouse_integration_2/trs-server/export/in_progress_bpo/201609081030
This was reproduced with the option stepwise=false, which means it traverses the subdirectories in a single step instead of step wise.
Still don’t know what best solution is.

Related

Moving file to another directory in ABAP

I have got a service running in a specific directory in 5-second-intervals which is picking up an XML file created in that directory sending it for some necessary authorization checks to another client and then requesting a response file.
My issue is that my Z_PROGRAM creating the XML file might take longer than 5 seconds as a result of the file's size. Therefore creating the file in that specific directory is not preferable. I thought about creating a new folder in that directory called "temporary" and creating the file inside that folder, then once I'm done with it, moving it back outside for the service to pick it up.
Is there any way to move files from one directory to another via ABAP code only?
Copying the file manually is not an option since the problem that I have during file creation still persists. I need 2 alternatives, one used for local directories and one for application server directories. Any ideas?
Generally, we create another empty file for completed files after the file creation process ends. Third parties must be firstly checked empty file is there. Example:
data file.csv
data file.ok
If you already completed your integration and it is not easy to make any change with third parties, I prefer using OS level file moving commands. Sample document here. You can use mv for Linux server and move for Windows. If your file is big, you will get same problem with OPEN DATASET concept. We have ARCHIVFILE_SERVER_TO_SERVER FM for moving files but it is also using OPEN DATASET.
there is no explicit move command in ABAP code that move or copy files between directories in application server.
there is two tips can be helpfull in your case. if you are writing big file you may seperate the logic behind collecting data and writing file. I would say don't execute transfer data inside your loop. instead collect you data into an internal table once you're done, loop over this internal table and write direclty strings without any delay you should be able to write a big files upp to several hundred of MB under 1 sec.
next tips is to not modify your program, or if you are using function modules to construct xml is, write to a temp directory after finishing, then have another program open you file on source directory by read dataset and directly write data to the new directory again just strings without interruptions.
you should be ok if you just write strings.
You can simply use System Call Commands to perform actions in Application Directory.
CALL 'SYSTEM'
ID 'COMMAND'
FIELD 'mv /usr/sap/temporary/File.xml
/usr/sap/final/file.xml'

Fuse/Camel: How to stop after downloading just one file

Fuse/Camel newbie here. I'm trying to automate a manual process where .done files are downloaded from an FTP host, then renamed "fileout.txt", and finally an AS/400 program is executed on that file.
However, the department hosting the AS/400 program doesn't have resources to update their programming. The solution I'm working toward is to have Camel download one file at a time, save it as "fileout.txt", then execute a JT400 program to process it. Individually those steps work but I'm left with one problem.
What I pray you, dear reader, can help me with is "How can I stop Camel after downloading just one file?
(since overwriting, appending, or downloading multiple files won't work for the following step)".
How can I stop Camel after downloading just one file?
You can set following parameters in FTP consumer
maxMessagesPerPoll=1 (Limit number of message to be download in single batch)
delay=500000 (Increase the time interval between each poll, so you have time to stop the route)
Then, your ftp route can trigger an asynchronous message (maybe wireTap component) to another route to trigger controlBus component to stop the ftp route by route id.
I'm trying to automate a manual process where .done files are downloaded from an FTP host, then renamed fileout.txt, and finally an AS/400 program is executed on that file
Other than stop/start your route, you may try pollEnrich component with FTP usage. Using pollEnrich, you can trigger FTP consumer once when needed if you know the target file name already.

Camel File Poller of a Mounted CIFS

We're experiencing a strange problem.
We have a file component monitoring a folder. This works perfectly if the path is either
a) myrelativepath - which is relative to the Karaf installation where the camel route is run; or
b) /tst/mypath - which reads from a folder from the root
If I set log level to DEBUG I see the logs of it polling based on my interval.
However, if I set the path to be:
/mnt/windowsshare - which is a mounted windows share.
I get nothing in the logs, I don't see the poll, and it doesn't pick up any files. apparently the route is started though.
Interestingly, I have another camel route which writes a file to that location (a subfolder called inbound) and it writes file with no problem.
Any ideas?
I can get perhaps more logs tomorrow, but this is only happening in this environment where we have a windows share. And the share seems to be fine.
For testing we have run Camel as root and as root on the commandline we have tested reading the files (via vi) and all is ok.
Any suggestions for things to look at?
Basically make sure you don't have too many files in the antexlcude...polling is logarithmic and a fraction more makes polling very slow.
Needs more code analysis and VM introspection to understand why.

Data loss on concurrent file write in camel

I am using camel technology for my file operation. My system is cluster environment.
Let say, I have 4 instances
Instance A
Instance B
Instance C
Instance D
Folders Structure
Input Folder: C:/app/input
Output Folder: C:/app/output
All the four instances will be pointing to Input folder location. As per, my business 8 files will be placed in the input folder and output will be consolidated file. here camel losing data when concurrently writing to output file.
Route:
from("file://C:/app/input")
.setHeader(Exchange.File_Name,simple("output.txt"))
.to("file://C:/app/output?fileExist=Append")
.end();
Kindly help me to resolve this issue. is there any thing like write lock in camel? to avoid concurrent file writer. Thanks in advance
You can use the doneFile option of the file component, see http://camel.apache.org/file2.html for more information.
Avoid reading files currently being written by another application
Beware the JDK File IO API is a bit limited in detecting whether another application is currently writing/copying a file. And the implementation can be different depending on OS platform as well. This could lead to that Camel thinks the file is not locked by another process and start consuming it. Therefore you have to do you own investigation what suites your environment. To help with this Camel provides different readLock options and doneFileName option that you can use. See also the section Consuming files from folders where others drop files directly.

Sharing file locks

I am currently working on a file processing service that looks at a fileshare, where files are uploaded to via FTP.
For scalability I've been asked to make this service to be able to be load balanced, so the service has to expect that other services on different machines may also be trying to process these files.
OK, so I thought I should be able achieve this by obtaining an exclusive lock for my process before processing a file, and skipping any files that may already be locked by another process.
The crux of this approach is shown below (I've left out the error handling for simplicity):
using(FileStream fs = File.Open(myFile, FileMode.Open, FileAccess.ReadWrite, (FileShare.Read | FileShare.Delete))
{
//Do work
}
Q1: My process now has a lock on this file. I thought this would mean I could then access the same file (without using the stream) and still have the correct access to it, but based on testing it seems I only have the benefits of the lock through the stream. Is this correct?
(For example, before I included FileShare.Delete, File.Delete(myFile) failed)
The above lock ultimately uses the 'Write' permission to determine which service has the file, but is intended to allow other processes to still Read the file. This is because the process that has the lock attempts to verify if the file is a valid zip file , which uses a third party library (Xceed.Zip). However this fails saying the file "is being used by another process". Using reflector I ultimately found the problematic call is:
stream = this.m_info.Open(FileMode.Open, FileAccess.Read, FileShare.Read);
Now I would have expected this to work as it only wants to read the file, but it fails. The reason appears to be outlined in a similar question. However, as this is a 3rd party API I can't change their code to use ReadWrite.
Q2: Is there a way I can correctly lock the file so it will not be picked up by the other services, but it can still be verified as a zip file using the external API?
I feel like there should be a 'correct' way to do this, but at the moment the best I can come up with is to lock the file, move it away from the shared directory, and then verify it at the new location.
If you're planning to reactively handle this situation by handling UnauthorizedAccessException I think you're making a serious mistake.
This can be handled by proactively renaming files. For example you can configure your service to only read files whose name is in the format 'Filename.YYYYMMDD.txt'. Prior to processing the file, you can rename it to 'Filename.YYYYMMDD.processing'. Then after processing the file you rename it to 'Filename.YYYYMMDD.done'.
You can even take it a step further by making another service that enqueues the filenames. This service will be a FileSystemWatcher that listens for FileAdd operations. Once it receives that event it proceeds to queueing the Filename to a global message queue. Then, each of your service will just be dequeueing filenames and no longer have to worry about concurrent access.
HTH

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