"Maximum parse depth exceeded" after upgrading from 19.10 to 19.11 #7668
Description
I'm not sure if this is a bug or intended behavior, from what I was able to investigate it was introduced in #6433 as a security bugfix, however I'm not quite sure if it's working as expected...
Describe the bug or unexpected behaviour
In ClickHouse 19.10 (and below) queries using roughly the following format (I've simplified it as much as I could) worked fine:
SELECT
arraySort(arrayMap((x, y) -> (x, y), groupArray(event_index), groupArray(url))) AS events,
arrayFilter(event -> (event.1 = step2.1 - 1), events)[1] AS step1,
arrayFilter(event -> (event.1 = step3.1 - 1), events)[1] AS step2,
arrayFilter(event -> (event.1 = step4.1 - 1), events)[1] AS step3,
arrayFilter(event -> (event.1 = step5.1 - 1), events)[1] AS step4,
arrayFilter(event -> (event.1 = step6.1 - 1), events)[1] AS step5,
arrayFilter(event -> (event.2 LIKE '%foo%'), events)[1] AS step6
FROM data
GROUP BY session_id
In ClickHouse 19.11 (and above) the same query throws an exception:
Received exception from server (version 19.11.13):
Code: 306. DB::Exception: Received from localhost:9000. DB::Exception: Received from clickhouse-cluster-3:9000. DB::Exception: Maximum parse depth exceeded.
How to reproduce
- This only happens on ClickHouse >=19.11
- Native interface, but probably does not matter
- Default settings, cluster with 2 shards and ReplicatedMergeTrees (2 servers in each shard) + Distributed tables
CREATE TABLE data_shard (
server_date Date,
session_id UInt64,
event_index UInt16,
url String
) ENGINE = ReplicatedMergeTree('/clickhouse/tables/default/{shard}/data', '{replica}') PARTITION BY toYYYYMM(server_date) ORDER BY (server_date, session_id) SETTINGS index_granularity = 8192;
CREATE TABLE data (
server_date Date,
session_id UInt64,
event_index UInt16,
url String
) ENGINE = Distributed(analytics, default, data_shard, rand());
Expected behavior
I would except the query to return results as it did in ClickHouse 19.10 and below.
Error message and/or stacktrace
Received exception from server (version 19.11.13):
Code: 306. DB::Exception: Received from localhost:9000. DB::Exception: Received from clickhouse-cluster-3:9000. DB::Exception: Maximum parse depth exceeded.
Oddly enough, I was unable to reproduce this issue on a single-server setup, which seems weird considering that it's a parsing exception 😕