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From Fay Hou [Storage Service] ­ <fay...@coupang.com>
Subject index_interval
Date Mon, 10 Jul 2017 22:09:05 GMT
BY defaults:

AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128

"Cassandra maintains index offsets per partition to speed up the lookup
process in the case of key cache misses (see cassandra read path overview
<http://docs.datastax.com/en/cassandra/2.1/cassandra/dml/dml_about_reads_c.html>).
By default it samples a subset of keys, somewhat similar to a skip list.
The sampling interval is configurable with min_index_interval and
max_index_interval CQL schema attributes (see describe table). For
relatively large blobs like HTML pages we seem to get better read latencies
by lowering the sampling interval from 128 min / 2048 max to 64 min / 512
max. For large tables like parsoid HTML with ~500G load per node this
change adds a modest ~25mb off-heap memory."

I wonder if any one has experience on working with max and min index_interval
to increase the read speed.

Thanks,
Fay

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