At Percona, we operate on the premise that full-transparency makes a product better. We strive to build the best open-source database products, but also to help you manage any issues that arise in any of the databases that we support. And, in true open source form, report back on any issues or bugs you might encounter along the way.
We constantly update our bug reports and monitor other boards to ensure we have the latest information, but we wanted to make it a little easier for you to keep track of the most critical ones. This new monthly post is a central place to get information on the most noteworthy open and recently resolved bugs.
In this edition of our monthly bug report, we have the following list of bugs:
Percona Server for MySQL/MySQL Bugs
PS-6800(MySQL#98142): Uncontrollable memory allocation with TRIGGERS, PROCEDURES, and FUNCTIONS
Affects Version/s: 5.7.29, 8.0.19
This is a critical bug because it will result in “Out Of Memory” for users who use routines extensively.
PS-6961(MySQL#99157): Event Scheduler memory leak
Affects Version/s: 5.6.47, 5.7.29, 8.0.19
Fixed Version: 5.6.48, 5.7.30, 8.0.20
Another critical memory leak bug due to events, as per the upstream update
This is a duplicate of Bug #97847, related Bug #95787
PS-7007(MySQL#99361) : MySQL 8.0: select count(*) query on information_schema.innodb_tables taking very long.
Affects Version/s: 8.0.19
Compared to 5.7, getting table metadata information from the 8.0 version information_schema is slow.
PS-6883(MySQL#98501): Exchanging partition with tables does not update SDI correctly
Affects Version/s: 8.0.18
In addition to storing metadata about database objects in the data dictionary, MySQL stores it in serialized form. This data is referred to as serialized dictionary information (SDI). InnoDB stores SDI data within its tablespace files.
Exchanging partition and Import tablespace, both operations can result in having wrong SDI in two places after an exchange.
PS-6876(MySQL#98700): MySQL 8 Crash with MASTER_COMPRESSION_ALGORITHMS / slave_compressed_protocol
Affects Version/s: 8.0.18
With slave_compressed_protocol option, MySQL will crash if the slave fails to connect to master and then later succeeds.
MySQL#92252: Mysql generates GTID gaps because of option slave-skip-errors
Affects Version/s: 5.7.23
As a result of this bug, you will notice the very large value for Executed_Gtid_Set in SHOW SLAVE STATUS output with gaps in GTIDs. As a result, SHOW SLAVE STATUS command may be failed due to large packet size if Executed_Gtid_Set value is too large as compared to max_packet_size value.
In such a case, increasing max_packet_size value will be a workaround.
MySQL#97531: Replication breakage with syntax error with GRANT management
Affects Version/s: 5.7.28, 8.0.18
Fixed Version: 8.0.20, 5.7.30
While an SQL statement was in the process of being rewritten for the binary log so that sensitive information did not appear in plain text, if a SHOW PROCESSLIST statement was used to inspect the query, the query could become corrupted when it was written to the binary log, causing replication to stop. Reported syntax error on the slave was due to a corrupt statement in the relay logs which is fixed in 8.0.20, 5.7.30 version. Now the process of rewriting the query is now kept private, and the query thread is updated only when rewriting is complete.
Percona XtraDB Cluster
PXC-2705: Cluster consistency broken by parallel LOAD DATA INFILE query
Affects Version/s: 5.7.27
Fixed Version: 5.7.29 (Future release)
In PXC, LOAD DATA INFILE processing will commit every 10000 rows. So large transactions due to LOAD DATA will be split into a series of small transactions. In case replicating nodes manage to commit split chunks of data while the writer hasn’t committed any yet. Then due to cert conflict, the writer attempts to re-try transaction, which results in a duplicate key error on the other cluster nodes.
Percona XtraBackup
PXB-2162: percona-xtrabackup-80 does not work with mysql 8.0.20
Affects Version/s: 8.0.11
Due to the InnoDB redo log format changes in MySQL 8.0.20, Xtrabackup-80 failed to take backup.
This is a critical bug since xtrabackup-80 can not be used with MySQL 8.0.20. As per the announcement on the Percona blog, the dev team identified the cause for this issue and is diligently working towards a new release that will safely solve this issue as soon as possible.
PXB-2101: PXB 8.0 –prepare crash if exchange partition happened
Affects Version/s: 8.0.9
The source of the bug is PS-6883(MySQL#98501), and as a result after taking backup of PS-6883 bug affected data xtrabackup will crash while preparing a backup.
Percona Toolkit
PT-1747:pt-online-schema-change rebuild_constraints and metadata locking on the child table
Affects Version/s: 3.0.13
A critical bug potentially affects those who rebuild tables with foreign keys.
PT-1792: Percona Toolkit (v3.1) compatibility with Aurora
The source of this issue is receiving incorrect Threads_running info from Aurora, this is an Aurora bug which is fixed in 2.07 Aurora version. To avoid this issue, an Aurora upgrade is needed to the latest version(>=2.07).
Percona Monitoring and Management (PMM)
PMM-5547: PMM Grafana issue with 100+ instance monitoring “proxy error: context canceled”
Affects Version/s: 2.4
Fixed Version: 2.5
From PMM 2.5 version monitoring 100+ instances under PMM works fine.
PMM-5365: PMM2 Client fails to send Query Analytics to Server
Affects Version/s: 2.4
Binary data in slow query log breaks pmm-agent with the warning “Failed to send QanCollect request.”
PMM-5626: PMM client 2.4.0 QAN not working for MongoDB
Affects Version/s: Documentation bug
Cause for this is insufficient privileges for mongo user used with PMM for MongoDB QAN.
PMM-4829: Mongodb Exporter can’t gather metrics from hidden nodes with default flags
Affects Version/s: mongodb_exporter version v0.10.0
This bug does not affect those who use pmm-admin instead of adding the mongodb_exporter “manually”.
This is a documentation bug. To monitor hidden nodes, users need to pass ?connect=direct parameter.
Example:
./mongodb_exporter
–mongodb.uri=admin:[email protected]:17003/admin/?connect=direct
Summary
We welcome community input and feedback on all our products. If you find a bug or would like to suggest an improvement or a feature, learn how in our post, How to Report Bugs, Improvements, New Feature Requests for Percona Products.
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As the only provider of distributions for all three of the most popular open source databases—PostgreSQL, MySQL, and MongoDB—Percona provides expertise, software, support, and services no matter the technology.
Whether its enabling developers or DBAs to realize value faster with tools, advice, and guidance, or making sure applications can scale and handle peak loads, Percona is here to help.
Percona is committed to being open source and preventing vendor lock-in. Percona contributes all changes to the upstream community for possible inclusion in future product releases.
