Github user franz1981 commented on the issue:

    https://github.com/apache/activemq-artemis/pull/2012
  
    @cshannon 
    Summarized:
    ```
    org.apache.activemq.artemis.core.server.impl.MessageReferenceImpl:
    Instance size: 72 bytes
    Space losses: 2 bytes internal + 4 bytes external = 6 bytes total
    
    org.apache.activemq.artemis.core.paging.cursor.PagedReferenceImpl:
    Instance size: 104 bytes
    Space losses: 1 bytes internal + 4 bytes external = 5 bytes total
    
    org.apache.activemq.artemis.core.server.impl.LastValueQueue$HolderReference:
    Instance size: 40 bytes
    Space losses: 3 bytes internal + 0 bytes external = 3 bytes total
    ```
    `Instance size` is the value you're searching for: I have attached the 
`Space losses` as well, because it
    is related to what @michaelandrepearce is saying: just adding that mere 4 
bytes reference (with heap < 32 Gb the JVM uses compressed oops by default) has 
added 4 bytes (external) of padding ie a total of 8 bytes of more space used.
    TBH that's a difficult choice: we have done recently many changes to make 
every protocol much GC "gentle" to allow scaling more easily, but @cshannon is 
right that there are monitoring/telemetry reasons very important to be achieved 
as well.
    You both have very good points :O
    
    



---

Reply via email to