Changes between Version 11 and Version 12 of jazz/09-09-02
- Timestamp:
- Jan 13, 2010, 12:03:01 PM (15 years ago)
Legend:
- Unmodified
- Added
- Removed
- Modified
-
jazz/09-09-02
v11 v12 3 3 * hadoop.nchc.org.tw 系統維護 4 4 * 近期仍常有 Kernel Panic 問題,懷疑主因是記憶體空間不足。 5 * [[Image( hadoop_kernel_panic.png,width=400)]]5 * [[Image(wiki:jazz/09-09-02:hadoop_kernel_panic.png,width=400)]] 6 6 * [追蹤一] HADOOP_HEAPSIZE 曾改為 1500MB 現下修至 1024MB - 實體記憶體只有 2GB,系統本身就會吃掉 1.5GB,若再額外執行 Map/Reduce 程式,使用 HEAP 1.5GB 就高達 3GB。縱使 SWAP 開 2GB,或許還是無濟於事。 7 7 {{{ 8 8 export HADOOP_HEAPSIZE=1024 9 9 }}} 10 * [[Image( mem_usage_of_hadoop_cluster.png,width=400)]]10 * [[Image(wiki:jazz/09-09-02:mem_usage_of_hadoop_cluster.png,width=400)]] 11 11 * [追蹤二] 實際會使用記憶體的程序有:datanode, tasktracker, mapper, reducer,因此 mapper 個數與 reducer 個數也會受限於實際記憶體大小 12 * [[Image( hadoop_task_mem_usage.png,width=400)]]12 * [[Image(wiki:jazz/09-09-02:hadoop_task_mem_usage.png,width=400)]] 13 13 14 14 * 資安教育訓練