[HDFS-8889] Erasure Coding: cover more test situations of datanode failure during client writing

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Release Note: There has been enough test cases for the datanode failures.
• Assignee: Li Bo
• Reporter: Li Bo
• Created: 12/Aug/15 05:43
• Updated: 13/Jan/16 07:50
• Resolved: 13/Jan/16 07:50

Description

Currently 9 streamers are working together for the client writing. A small number of failed datanodes (<= 3) for a block group should not influence the writing. There’re a lot of datanode failure cases and we should cover as many as possible in unit test.
Suppose streamer 4 fails, the following situations for the next block group should be considered:
1) all streamers succeed
2) Streamer 4 still fails
3) only streamer 1 fails
4) only streamer 8 fails (test parity streamer)
5) streamer 4 and 6 fail
6) streamer 4 and 1,6 fail
7) streamer 4 and 1,2,6 fail
8) streamer 2, 6 fail
Suppose streamer 2 and 4 fail, the following situations for the next block group should be considered:
1) only streamer 2 and 4 fail
2) streamer 2, 4, 8 fail
3) only streamer 2 fails
4) streamer 3 , 8 fail
For a single streamer, we should consider the following situations of the time of datanode failure:
1) before writing the first byte
2) before finishing writing the first cell
3) right after finishing writing the first cell
4) before writing the last byte of the block
Other situations:
1) more than 3 streamers fail at the first block group
2) more than 3 streamers fail at the last block group
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