On Mon, Sep 26, 2016 at 6:09 PM, Gary Gregory <garydgreg...@gmail.com> wrote:
> On Mon, Sep 26, 2016 at 5:21 PM, Ralph Goers <ralph.go...@dslextreme.com> > wrote: > >> I thought you didn’t want to write to a file? >> > > I do not but if the buffer is large enough, log events should stay in RAM. > But it is not quite right anyway because I'd have to interpret the contents > of the file to turn back into log events. > > I started reading up on the Chronicle appender; thank you Remko for > pointing it out. > > An appender to a cache of objects is really want I want since I also want > to be able to evict the cache. TBC... > Like a JSR-107 Appender... Gary > > Gary > > >> The Chronicle stuff Remko is linking to is also worth exploring. >> >> Ralph >> >> >> >> On Sep 26, 2016, at 5:04 PM, Gary Gregory <garydgreg...@gmail.com> wrote: >> >> oh... what about our own http://logging.apache.org/ >> log4j/2.x/manual/appenders.html#MemoryMappedFileAppender >> >> ? >> >> Gary >> >> On Mon, Sep 26, 2016 at 4:59 PM, Remko Popma <remko.po...@gmail.com> >> wrote: >> >>> In addition to the Flume based solution, here is another alternative >>> idea: use Peter Lawrey's Chronicle[1] library to store log events in a >>> memory mapped file. >>> >>> The appender can just keep adding events without worrying about >>> overflowing the memory. >>> >>> The client that reads from this file can be in a separate thread (even a >>> separate process by the way) and can read as much as it wants, and send it >>> to the server. >>> >>> Serialization: You can either serialize log events to the target format >>> before storing them in Chronicle (so you have binary blobs in each >>> Chronicle excerpt), client reads these blobs and sends them to the server >>> as is. Or you can use the Chronicle Log4j2 appender[2] to store the events >>> in Chronicle format. The tests[3] show how to read LogEvent objects from >>> the memory mapped file, and the client would be responsible for serializing >>> these log events to the target format before sending data to the server. >>> >>> [1]: https://github.com/peter-lawrey/Java-Chronicle >>> [2]: https://github.com/OpenHFT/Chronicle-Logger >>> [3]: https://github.com/OpenHFT/Chronicle-Logger/blob/master >>> /logger-log4j-2/src/test/java/net/openhft/chronicle/logger/l >>> og4j2/Log4j2IndexedChronicleTest.java >>> >>> Remko >>> >>> Sent from my iPhone >>> >>> On 2016/09/27, at 5:57, Gary Gregory <garydgreg...@gmail.com> wrote: >>> >>> Please allow me to restate the use case I have for the >>> CollectionAppender, which is separate from any Flume-based or Syslog-based >>> solution, use cases I also have. Well, I have a Syslog use case, and >>> whether or not Flume is in the picture will really be a larger discussion >>> in my organization due to the requirement to run a Flume Agent.) >>> >>> A program (like a JDBC driver already using Log4j) communicates with >>> another (like a DBMS, not written in Java). The client and server >>> communicate over a proprietary socket protocol. The client sends a list of >>> buffers (in one go) to the server to perform one or more operations. One >>> kind of buffer this protocol defines is a log buffer (where each log event >>> is serialized in a non-Java format.) This allows each communication from >>> the client to the server to say "This is what's happened up to now". What >>> the server does with the log buffers is not important for this discussion. >>> >>> What is important to note is that the log buffer and other buffers go to >>> the server in one BLOB; which is why I cannot (in this use case) send log >>> events by themselves anywhere. >>> >>> I see that something (a CollectionAppender) must collect log events >>> until the client is ready to serialize them and send them to the server. >>> Once the events are drained out of the Appender (in one go by just getting >>> the collection), events can collect in a new collection. A synchronous >>> drain operation would create a new collection and return the old one. >>> >>> The question becomes: What kind of temporary location can the client use >>> to buffer log event until drain time? A Log4j Appender is a natural place >>> to collect log events since the driver uses Log4j. The driver will make its >>> business to drain the appender and work with the events at the right time. >>> I am thinking that the Log4j Appender part is generic enough for inclusion >>> in Log4j. >>> >>> Further thoughts? >>> >>> Thank you all for reading this far! >>> Gary >>> >>> On Sun, Sep 25, 2016 at 1:20 PM, Ralph Goers <ralph.go...@dslextreme.com >>> > wrote: >>> >>>> I guess I am not understanding your use case quite correctly. I am >>>> thinking you have a driver that is logging and you want those logs >>>> delivered to some other location to actually be written. If that is your >>>> use case then the driver needs a log4j2.xml that configures the >>>> FlumeAppender with either the memory or file channel (depending on your >>>> needs) and points to the server(s) that is/are to receive the events. The >>>> FlumeAppender handles sending them in batches with whatever size you want >>>> (but will send them in smaller amounts if they are in the channel too >>>> long). Of course you would need the log4j-flume and flume jars. So on the >>>> driver side you wouldn’t need to write anything, just configure the >>>> appender and make sure the jars are there. >>>> >>>> For the server that receives them you would also need Flume. Normally >>>> this would be a standalone component, but it really wouldn’t be hard to >>>> incorporate it into some other application. The only thing you would have >>>> to write would be the sink that writes the events to the database or >>>> whatever. To incorporate it into an application you would have to look at >>>> the main() method of flume and covert that to be a thread that you kick >>>> off. >>>> >>>> Ralph >>>> >>>> >>>> >>>> On Sep 25, 2016, at 12:01 PM, Gary Gregory <garydgreg...@gmail.com> >>>> wrote: >>>> >>>> Hi Ralph, >>>> >>>> Thanks for your feedback. Flume is great in the scenarios that do not >>>> involve sending a log buffer from the driver itself. >>>> >>>> I can't require a Flume Agent to be running 'on the side' for the use >>>> case where the driver chains a log buffer at the end of the train of >>>> database IO buffer. For completeness talking about this Flume scenario, if >>>> I read you right, I also would need to write a custom Flume sink, which >>>> would also be in memory, until the driver is ready to drain it. Or, I could >>>> query some other 'safe' and 'reliable' Flume sink that the driver could >>>> then drain of events when it needs to. >>>> >>>> Narrowing down on the use case where the driver chains a log buffer at >>>> the end of the train of database IO buffer, I'll think I have to see about >>>> converting the Log4j ListAppender into a more robust and flexible version. >>>> I think I'll call it a CollectionAppender and allow various Collection >>>> implementations to be plugged in. >>>> >>>> Gary >>>> >>>> Gary >>>> >>>> On Sat, Sep 24, 2016 at 3:44 PM, Ralph Goers < >>>> ralph.go...@dslextreme.com> wrote: >>>> >>>>> If you are buffering events in memory you run the risk of losing >>>>> events if something should fail. >>>>> >>>>> That said, if I had your requirements I would use the FlumeAppender. >>>>> It has either an in-memory option to buffer as you are suggesting or it >>>>> can >>>>> write to a local file to prevent data loss if that is a requirement. It >>>>> already has the configuration options you are looking for and has been >>>>> well >>>>> tested. The only downside is that you need to have either a Flume instance >>>>> receiving the messages are something that can receive Flume events over >>>>> Avro, but it is easier just to use Flume and write a custom sink to do >>>>> what >>>>> you want with the data. >>>>> >>>>> Ralph >>>>> >>>>> On Sep 24, 2016, at 3:13 PM, Gary Gregory <garydgreg...@gmail.com> >>>>> wrote: >>>>> >>>>> Hi All, >>>>> >>>>> I can't believe it, but through a convoluted use-case, I actually need >>>>> an in-memory list appender, very much like our test-only ListAppender. >>>>> >>>>> The requirement is as follows. >>>>> >>>>> We have a JDBC driver and matching proprietary database that >>>>> specializes in data virtualization of mainframe resources like DB2, VSAM, >>>>> IMS, and all sorts of non-SQL data sources ( >>>>> http://www.rocketsoftware.com/products/rocket-data/rocket-d >>>>> ata-virtualization) >>>>> >>>>> The high level requirement is to merge the driver log into the >>>>> server's log for full-end to end tractability and debugging. >>>>> >>>>> When the driver is running on the z/OS mainframe, it can be configured >>>>> with a z/OS specific Appender that can talk to the server log module >>>>> directly. >>>>> >>>>> When the driver is running elsewhere, it can talk to the database via >>>>> a Syslog socket Appender. This requires more set up on the server side and >>>>> for the server to do special magic to know how the incoming log events >>>>> match up with server operations. Tricky. >>>>> >>>>> The customer should also be able to configure the driver such that >>>>> anytime the driver communicates to the database, it sends along whatever >>>>> log events have accumulated since the last client-server roundtrip. This >>>>> allows the server to match exactly the connection and operations the >>>>> client >>>>> performed with the server's own logging. >>>>> >>>>> In order to do that I need to buffer all log events in an Appender and >>>>> when it's time, I need to get the list of events and reset the appender to >>>>> a new empty list so events can keep accumulating. >>>>> >>>>> My proposal is to either turn our ListAppender into such an appender. >>>>> For sanity, the appender could be configured with various sizing policies: >>>>> >>>>> - open: the list grows unbounded >>>>> - closed: the list grows to a given size and _new_ events are dropped >>>>> on the floor beyond that >>>>> - latest: the list grows to a given size and _old_ events are dropped >>>>> on the floor beyond that >>>>> >>>>> Thoughts? >>>>> >>>>> Gary >>>>> >>>>> -- >>>>> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org >>>>> Java Persistence with Hibernate, Second Edition >>>>> <http://www.manning.com/bauer3/> >>>>> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> >>>>> Spring Batch in Action <http://www.manning.com/templier/> >>>>> Blog: http://garygregory.wordpress.com >>>>> Home: http://garygregory.com/ >>>>> Tweet! http://twitter.com/GaryGregory >>>>> >>>>> >>>>> >>>> >>>> >>>> -- >>>> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org >>>> Java Persistence with Hibernate, Second Edition >>>> <http://www.manning.com/bauer3/> >>>> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> >>>> Spring Batch in Action <http://www.manning.com/templier/> >>>> Blog: http://garygregory.wordpress.com >>>> Home: http://garygregory.com/ >>>> Tweet! http://twitter.com/GaryGregory >>>> >>>> >>>> >>> >>> >>> -- >>> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org >>> Java Persistence with Hibernate, Second Edition >>> <http://www.manning.com/bauer3/> >>> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> >>> Spring Batch in Action <http://www.manning.com/templier/> >>> Blog: http://garygregory.wordpress.com >>> Home: http://garygregory.com/ >>> Tweet! http://twitter.com/GaryGregory >>> >>> >> >> >> -- >> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org >> Java Persistence with Hibernate, Second Edition >> <http://www.manning.com/bauer3/> >> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> >> Spring Batch in Action <http://www.manning.com/templier/> >> Blog: http://garygregory.wordpress.com >> Home: http://garygregory.com/ >> Tweet! http://twitter.com/GaryGregory >> >> >> > > > -- > E-Mail: garydgreg...@gmail.com | ggreg...@apache.org > Java Persistence with Hibernate, Second Edition > <http://www.manning.com/bauer3/> > JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> > Spring Batch in Action <http://www.manning.com/templier/> > Blog: http://garygregory.wordpress.com > Home: http://garygregory.com/ > Tweet! http://twitter.com/GaryGregory > -- E-Mail: garydgreg...@gmail.com | ggreg...@apache.org Java Persistence with Hibernate, Second Edition <http://www.manning.com/bauer3/> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> Spring Batch in Action <http://www.manning.com/templier/> Blog: http://garygregory.wordpress.com Home: http://garygregory.com/ Tweet! http://twitter.com/GaryGregory
