feat(rocksdb): Support more configurable items for bloom filter

[acelyc111]

What problem does this PR solve?

• Support to config bits_per_key for Bloom filter to provide lower false positive rate
• Support to config format_version for SST to provide a faster and more accurate Bloom filter implementation

What is changed and how it works?

Add config in replica server's config.ini:

[pegasus.server]
rocksdb_bloom_filter_bits_per_key = 10
rocksdb_format_version = 2

Check List

Tests

• Manual test (add detailed scripts or steps below)

1. Write test data set A
2. Read test data set B, whose hashkey scale size is 100 times larger than test data set A.
   So 99% of these items are not exist, but these point lookups will consult Bloom filters, then negative or positive will be returned by Bloom filters to indicate whether the key is definity not exist or may exist.
3. Oberve point_fp_rate in shell command app_stat

Result

• When rocksdb_bloom_filter_bits_per_key = 10 and rocksdb_format_version = 2

>>> app_stat -a test
[app_stat]
pidx          GET  MGET   PUT  ...  point_n_rate  point_fp_rate
0            0.00  0.00  0.00  ...      0.960577       0.011309
1            0.00  0.00  0.00  ...      0.960897       0.010979
2            0.00  0.00  0.00  ...      0.961837       0.009758
3            0.00  0.00  0.00  ...      0.961982       0.009609
4            0.00  0.00  0.00  ...      0.960831       0.010793
5            0.00  0.00  0.00  ...      0.961616       0.009985
6            0.00  0.00  0.00  ...      0.961044       0.010783
7            0.00  0.00  0.00  ...      0.959726       0.012140
(total:8)    0.00  0.00  0.00  ...      0.961064       0.010670

• When rocksdb_bloom_filter_bits_per_key = 24 and rocksdb_format_version = 2

>>> app_stat -a test_v2_b24
[app_stat]
pidx          GET  MGET   PUT  ...  point_n_rate  point_fp_rate
0            0.00  0.00  0.00  ...      0.997455       0.002545
1            0.00  0.00  0.00  ...      0.997706       0.002294
2            0.00  0.00  0.00  ...      0.997608       0.002392
3            0.00  0.00  0.00  ...      0.997616       0.002384
4            0.00  0.00  0.00  ...      0.997608       0.002392
5            0.00  0.00  0.00  ...      0.997591       0.002409
6            0.00  0.00  0.00  ...      0.997116       0.002884
7            0.00  0.00  0.00  ...      0.997156       0.002844
(total:8)    0.00  0.00  0.00  ...      0.997482       0.002518

• When rocksdb_bloom_filter_bits_per_key = 24 and rocksdb_format_version = 5

>>> app_stat -a test_v5_b24
[app_stat]
pidx          GET  MGET   PUT  ...  point_n_rate  point_fp_rate
0            0.00  0.00  0.00  ...      0.999933       0.000067
1            0.00  0.00  0.00  ...      0.999944       0.000056
2            0.00  0.00  0.00  ...      0.999965       0.000035
3            0.00  0.00  0.00  ...      0.999920       0.000080
4            0.00  0.00  0.00  ...      0.999944       0.000056
5            0.00  0.00  0.00  ...      0.999955       0.000045
6            0.00  0.00  0.00  ...      0.999944       0.000056
7            0.00  0.00  0.00  ...      0.999965       0.000035
(total:8)    0.00  0.00  0.00  ...      0.999946       0.000054

Code changes

• Has exported function/method change
  No
• Has exported variable/fields change
  No
• Has interface methods change
  No
• Has persistent data change
  Yes

Side effects

• Possible performance regression
  No
• Increased code complexity
  No
• Breaking backward compatibility

1. New version of Pegasus can read bloom filter normally when rocksdb_format_version is 2 or 5
2. Old version of Pegasus can ONLY read bloom filter normally when rocksdb_format_version is 2
3. Old version of Pegasus would see the new structure as corrupt filter data and read the table as if there's no filter

Related changes

• Need to cherry-pick to the release branch
  Yes
• Need to update the documentation
  Yes
• Need to be included in the release note
  Yes