[CASSANDRA-13127] Materialized Views: View row expires too soon

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Duplicate
• Component/s: Feature/Materialized Views, Legacy/Local Write-Read Paths
• Severity: Normal
• Assignee: Zhao Yang
• Reporter: Duarte Nunes

Authors

Zhao Yang

• Created: 16/Jan/17 20:18
• Updated: 16/Apr/19 09:30
• Resolved: 26/Jul/17 09:54

Description

Consider the following commands, ran against trunk:

echo "DROP MATERIALIZED VIEW ks.mv; DROP TABLE ks.base;" | bin/cqlsh
echo "CREATE TABLE ks.base (p int, c int, v int, PRIMARY KEY (p, c));" | bin/cqlsh
echo "CREATE MATERIALIZED VIEW ks.mv AS SELECT p, c FROM base WHERE p IS NOT NULL AND c IS NOT NULL PRIMARY KEY (c, p);" | bin/cqlsh
echo "INSERT INTO ks.base (p, c) VALUES (0, 0) USING TTL 10;" | bin/cqlsh
# wait for row liveness to get closer to expiration
sleep 6;
echo "UPDATE ks.base USING TTL 8 SET v = 0 WHERE p = 0 and c = 0;" | bin/cqlsh
echo "SELECT p, c, ttl(v) FROM ks.base; SELECT * FROM ks.mv;" | bin/cqlsh

 p | c | ttl(v)
---+---+--------
 0 | 0 |      7

(1 rows)

 c | p
---+---
 0 | 0

(1 rows)

# wait for row liveness to expire
sleep 4;
echo "SELECT p, c, ttl(v) FROM ks.base; SELECT * FROM ks.mv;" | bin/cqlsh


 p | c | ttl(v)
---+---+--------
 0 | 0 |      3

(1 rows)

 c | p
---+---

(0 rows)

Notice how the view row is removed even though the base row is still live. I would say this is because in ViewUpdateGenerator#computeLivenessInfoForEntry the TTLs are compared instead of the expiration times, but I'm not sure I'm getting that far ahead in the code when updating a column that's not in the view.

Issue Links

• is duplicated by: CASSANDRA-11500 Obsolete MV entry may not be properly deleted
• is related to: CASSANDRA-6782 setting TTL on some columns seems to expire whole row
• is related to: CASSANDRA-11475 MV code refactor
• relates to: CASSANDRA-13547 Filtered materialized views missing data
• relates to: CASSANDRA-11500 Obsolete MV entry may not be properly deleted
• relates to: CASSANDRA-13409 Materialized Views: View cells are resurrected