Rajika, On Mon, May 3, 2010 at 5:30 PM, Rajika Kumarasiri <[email protected]> wrote:
> > > On Mon, May 3, 2010 at 4:42 PM, Hiranya Jayathilaka > <[email protected]>wrote: > >> >> >> On Mon, May 3, 2010 at 4:24 PM, Rajika Kumarasiri <[email protected]>wrote: >> >>> >>> >>> On Mon, May 3, 2010 at 4:15 PM, Hiranya Jayathilaka < >>> [email protected]> wrote: >>> >>>> Rajika, >>>> >>>> On Mon, May 3, 2010 at 3:44 PM, Rajika Kumarasiri <[email protected]>wrote: >>>> >>>>> I'd like to hear your feedback before I provide you with a patch for >>>>> the issue[1]. First it's an important improvement to vfs-transport. >>>>> I think we can fix the problem by introducing an optional parameter for >>>>> the vfs transport , "transport.vfs.TempFileName". >>>> >>>> >>>> Why does the user has to specify this? >>>> >>> No, it should be an indicator ( a boolean) which suggest to use a temp >>> file or not. >>> >> >> Why? Writing to a temp file and then moving the file to the appropriate >> place is the safest approach for handling file uploads. >> > > Currently when uploading a file using the vfs transport sender it'll use > the provided file name (as a part of the url) as the file name at the ftp > server. As you can see this has a problem if one on the ftp server side > starts to process the file at the same time since the file is not fully > transferred. > To avoid this we'll use a temporary file(if the user need a one) at the ftp > server for uploading the file, once uploading is completed we can move that > temp file to the original one. > IMO this has to be the default behavior. Almost all the time user does not have any control over how and when the receiving application reads files from the file system. So there is always a chance that the receiving application may try to read from a file while Synapse is writing to it. So Synapse should always anticipate this scenario and it should always do the right thing, which is to write the content to a temp file and then move it to the correct location. For instance we might run into this problem with Synapse itself. Imagine we have two Synapse instances. One is writing files to a given directory and the other instance is polling on that directory. Without the above described approach the second Synapse instance may pick up a half done file. If you really need to make this configurable, I would still say make this the default behavior and provide a way to turn it off if required. Thanks, Hiranya > Rajika > > >> >> Thanks, >> Hiranya >> >> >>> >>> Rajika >>> >>> >>>> I think this behavior should be there by default in the transport. The >>>> transport should figure out suitable names for temp files. Also I don't >>>> think we can use a single name for all temp files. There could be >>>> situations >>>> where multiple worker threads are trying to upload several files to the >>>> same >>>> server. >>>> >>>> Thanks, >>>> Hiranya >>>> >>>> >>>>> If a user has provided this parameter we'll use this file on the >>>>> remote server to upload the file. Once the upload is completed we will >>>>> move >>>>> the temporary file to the original file(which will delete the temp file). >>>>> Comments? Suggestions? >>>>> >>>>> Rajika >>>>> >>>>> [1] - https://issues.apache.org/jira/browse/SYNAPSE-502 >>>>> >>>>> -- >>>>> http://rajikak.blogspot.com/ >>>>> >>>> >>>> >>>> >>>> -- >>>> Hiranya Jayathilaka >>>> Software Engineer; >>>> WSO2 Inc.; http://wso2.org >>>> E-mail: [email protected]; Mobile: +94 77 633 3491 >>>> Blog: http://techfeast-hiranya.blogspot.com >>>> >>> >>> >>> >>> -- >>> http://rajikak.blogspot.com/ >>> >> >> >> >> -- >> Hiranya Jayathilaka >> Software Engineer; >> WSO2 Inc.; http://wso2.org >> E-mail: [email protected]; Mobile: +94 77 633 3491 >> Blog: http://techfeast-hiranya.blogspot.com >> > > > > -- > http://rajikak.blogspot.com/ > -- Hiranya Jayathilaka Software Engineer; WSO2 Inc.; http://wso2.org E-mail: [email protected]; Mobile: +94 77 633 3491 Blog: http://techfeast-hiranya.blogspot.com
