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ed70ed6f71
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516 Commits

Author SHA1 Message Date
Azat Khuzhin
ed70ed6f71 Introduce connection_no_wait setting for MySQL engine. 
This will allow to avoid superfluous sleep during query execution, since
this not only not desired behavoiur, but also may hang the server, since
if you will execute enough queries that will use MySQL database but will
not allow enough connections (or your MySQL server is too slow) then you
may run out of threads in the global thread pool.

Also note that right now it is possible to get deadlock when the mysql
pool is full, consider the following scenario:

- you have m1 and m2 mysql tables
- you have q1 and q2 queries, bot queries join m1 and m2
- q1 allocated connection for m1 but cannot allocate connection for m2
- q2 allocated connection for m2 but cannot allocate connection for m1
- but to resolve the lock one should give up on the locking while it is not possible right now...

And then you got no free threads and this:

    # grep -h ^202 /proc/$(pgrep clickhouse-serv)/task/*/syscall  | cut -d' ' -f2 | sort | uniq -c | sort -nr | head
       1554 0x7ffb60b92fe8 # mutex in mysqlxx::PoolWithFailover::get
       1375 0x7ffb9f1c4748 # mutex in ::PoolEntryHelper::~PoolEntryHelper from DB::MultiplexedConnections::invalidateReplica
       1160 0x7ffb612918b8 # mutex in mysqlxx::PoolWithFailover::get
         42 0x7ffb9f057984 # mutex in ThreadPoolImpl<std::__1::thread>::worker

    *NOTE: 202 is a `futex` with WAIT*

(Went with `syscall` because debugging 10k+ threads is not easy, and
eventually it may TRAP)
 2021-09-02 22:23:37 +03:00
alexey-milovidov
ff0b332c24
Update custom-partitioning-key.md 2021-09-01 20:53:06 +03:00
alexey-milovidov
4699386470
Update mergetree.md 2021-09-01 20:52:05 +03:00
Zhichang Yu
ef1994f420 set env LIBHDFS3_CONF, refers to ClickHouse#8159 2021-08-28 09:16:48 +08:00
Kseniia Sumarokova
31afd7d09c
Merge pull request #28081 from kssenii/pg-conflict 
Support `on conflict` for postgres engine
 2021-08-26 16:30:30 +03:00
Nikolai Kochetov
11d79ec24f
Merge pull request #27725 from olgarev/revolg-DOCSUP-12894-projections_translated 
DOCSUP-12894: Projections settings
 2021-08-26 11:26:58 +03:00
olgarev
89a4ca27ae
Apply suggestions from code review 
Co-authored-by: Alexey Boykov <33257111+mathalex@users.noreply.github.com>
 2021-08-25 15:15:39 +03:00
kssenii
0ec716292c Postgres ON CONFLICT 2021-08-24 12:37:32 +00:00
Kruglov Pavel
86f89af4d2
Merge pull request #28077 from Avogar/fix-typo-in-docks 
Fix typo in docs
 2021-08-24 13:50:52 +03:00
Pavel Kruglov
f31b67238d Fix typo 2021-08-24 13:49:59 +03:00
alesapin
80085bd988
Merge pull request #27989 from olgarev/revolg-DOCSUP-13334-Recompression_TTL 
DOCSUP-13334: Recompression TTL and Settings
 2021-08-24 10:14:45 +03:00
olgarev
2aaa5eb584 Removed 2021-08-23 14:31:42 +00:00
olgarev
7d8436e690
Update docs/en/engines/table-engines/mergetree-family/mergetree.md 
Co-authored-by: alesapin <alesapin@gmail.com>
 2021-08-23 17:14:30 +03:00
olgarev
1448e1cefc
Apply suggestions from code review 
Co-authored-by: alesapin <alesapin@gmail.com>
 2021-08-23 17:13:50 +03:00
olgarev
4625bc9e77
Update docs/en/engines/table-engines/mergetree-family/mergetree.md 
Co-authored-by: alesapin <alesapin@gmail.com>
 2021-08-23 17:10:55 +03:00
olgarev
21627e7be4
Apply suggestions from code review 2021-08-22 22:06:42 +03:00
olgarev
a11bebc082
Update docs/en/engines/table-engines/mergetree-family/mergetree.md 
Co-authored-by: Anna <42538400+adevyatova@users.noreply.github.com>
 2021-08-22 22:04:31 +03:00
olgarev
9af0ff311f
Update docs/en/engines/table-engines/mergetree-family/mergetree.md 
Co-authored-by: Anna <42538400+adevyatova@users.noreply.github.com>
 2021-08-22 22:03:56 +03:00
olgarev
9ebae04cfe
Update docs/en/engines/table-engines/mergetree-family/mergetree.md 
Co-authored-by: Anna <42538400+adevyatova@users.noreply.github.com>
 2021-08-22 22:03:41 +03:00
Kseniia Sumarokova
a08fde9226
Merge pull request #27703 from adevyatova/annadevyatova-DOCSUP-11655-sqlite 
DOCSUP-11655: Document the SQLite
 2021-08-22 21:46:44 +03:00
Anna
a7469d5686
Update sqlite.md 
Update
 2021-08-22 20:28:47 +03:00
Anna
fe8531c9f0
Update sqlite.md 
Added example this "INSERT" query
 2021-08-22 20:21:09 +03:00
olgarev
696a0b3db0 Recompression TTL and settings 2021-08-22 14:53:44 +00:00
olgarev
beaabd6fd5 Merge branch 'revolg-DOCSUP-12894-projections_translated' of https://github.com/olgarev/ClickHouse into revolg-DOCSUP-12894-projections_translated 2021-08-21 13:56:15 +00:00
olgarev
12218fd973 Merge branch 'master' into revolg-DOCSUP-12894-projections_translated 2021-08-21 13:54:24 +00:00
Kseniia Sumarokova
ac26e03cb4
Update docs/en/engines/database-engines/sqlite.md 2021-08-20 20:42:56 +03:00
olgarev
29b18d6bdc
Apply suggestions from code review 
Co-authored-by: Anna <42538400+adevyatova@users.noreply.github.com>
 2021-08-20 15:36:25 +03:00
adevyatova
c402670239 Add ru translation 2021-08-20 10:34:42 +00:00
Anna
ad5ca57c7f
Update docs/en/engines/table-engines/integrations/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:30:43 +03:00
Anna
a871916153
Update docs/en/engines/table-engines/integrations/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:29:26 +03:00
Anna
b9f2ed45a2
Update docs/en/engines/table-engines/integrations/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:29:21 +03:00
Anna
2644f7a48e
Update docs/en/engines/table-engines/integrations/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:29:12 +03:00
Anna
842d520967
Update docs/en/engines/table-engines/integrations/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:29:02 +03:00
Anna
77da21a1ba
Update docs/en/engines/table-engines/integrations/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:28:41 +03:00
Anna
cc44b54a58
Update docs/en/engines/database-engines/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:28:24 +03:00
Anna
dd6273fec4
Update docs/en/engines/database-engines/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:28:12 +03:00
Anna
be2a12a726
Update docs/en/engines/database-engines/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:27:56 +03:00
Anna
9a84270658
Update docs/en/engines/database-engines/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:27:42 +03:00
Anna
b891af816b
Update docs/en/engines/database-engines/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:27:36 +03:00
Anna
62f0517e31
Update docs/en/engines/database-engines/sqlite.md 
Co-authored-by: olgarev <56617294+olgarev@users.noreply.github.com>
 2021-08-19 07:27:24 +03:00
adevyatova
fcf3413ac9 Small fixes 2021-08-18 13:40:09 +00:00
adevyatova
4fb4387180 Added examples 2021-08-18 13:32:34 +00:00
Alexey Boykov
29ff255601
Merge pull request #27786 from KazeZlat/patch-1 
Added attention for ALTER on Buffer table prior to 28.10.2020
 2021-08-18 14:41:09 +03:00
tavplubix
a2ffc2f896
Merge pull request #27759 from olgarev/revolg-DOCSUP-12413-macros_support_in_functions_cluster 
DOCSUP-12413: macros support in functions cluster and clusterAllReplicas
 2021-08-18 13:00:49 +03:00
Nikita Mikhalev
62abef73f1
Improved phrasing of attention about ALTER on Buffer table 
Co-authored-by: Alexey Boykov <33257111+mathalex@users.noreply.github.com>
 2021-08-18 10:24:42 +05:00
Maksim Kita
32ee8618b7
Merge pull request #27533 from den-crane/patch-23 
Doc. graphitemergetree added info about AVG
 2021-08-17 21:21:42 +03:00
Alexander Kuzmenkov
c0e1c42562
Merge pull request #27536 from adevyatova/annadevyatova-DOCSUP-11968-explain 
DOCSUP-11968: Document the SQL-statement EXPLAIN ESTIMATE
 2021-08-17 16:50:34 +03:00
Nikita Mikhalev
189ad46206
Added attention for ALTER on Buffer table prior to 28.10.2020 2021-08-17 17:30:05 +05:00
Vitaly Baranov
50b4ca7650
Merge pull request #27362 from sevirov/sevirov-DOCSUP-12128-data_encryption_on_vfs_level 
DOCSUP-12128: Data encryption on VFS level
 2021-08-17 12:12:09 +03:00
Denny Crane
344016ee0e
Update graphitemergetree.md 2021-08-17 00:15:07 -03:00