What python can learn from java

transcript

What Python can learn from Javajbellis@datastax.com

Saturday, September 10, 2011

(Not a web development perspective)

Lesson one: GC

✤ Hotspot GC✤ Pluggable✤ Well-documented (http://java.sun.com/j2se/reference/

whitepapers/memorymanagement_whitepaper.pdf)✤ Tuneable (http://www.slideshare.net/ludomp/gc-tuning-in-the-

hotspot-java-vm-a-fisl-10-presentation)

Troubleshooting OOM

Troubleshooting fragmentation

http://www.cloudera.com/blog/2011/02/avoiding-full-gcs-in-hbase-with-memstore-local-allocation-buffers-part-2/

Lesson 2: Concurrency

✤ For CPU-bound applications, copies are the enemy✤ Corollary: you need to support threads + shared state

✤ Actor model✤ Multi-process + sysv

java.util.concurrent: ahead of its time

✤ ConcurrentSkipListMap✤ CopyOnWriteArrayList✤ NonblockingHashMap*✤ Atomic[Int|Long|Reference|...]✤ SynchronousQueue ✤ Java 7: TransferQueue✤ ThreadPoolExecutor, ScheduledThreadPoolExecutor

✤ FutureTask

Shared state = good, Mutable state = bad

✤ guava: Immutable collections✤ http://code.google.com/p/guava-libraries/

✤ Persistent collections✤ http://code.google.com/p/pcollections/✤ (More accurately, “What Python can learn from Haskell”)

What python can learn from java

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