MySQL 9.0 Reference Manual Including MySQL NDB Cluster 9.0
The MySQL Performance Schema provides instrumentation for performance monitoring of Group Replication memory usage. To view the available Group Replication instrumentation, issue the following query:
mysql>SELECT NAME,ENABLED FROM performance_schema.setup_instruments
WHERE NAME LIKE 'memory/group_rpl/%';
+-------------------------------------------------------------------+---------+ | NAME | ENABLED | +-------------------------------------------------------------------+---------+ | memory/group_rpl/write_set_encoded | YES | | memory/group_rpl/certification_data | YES | | memory/group_rpl/certification_data_gc | YES | | memory/group_rpl/certification_info | YES | | memory/group_rpl/transaction_data | YES | | memory/group_rpl/sql_service_command_data | YES | | memory/group_rpl/mysql_thread_queued_task | YES | | memory/group_rpl/message_service_queue | YES | | memory/group_rpl/message_service_received_message | YES | | memory/group_rpl/group_member_info | YES | | memory/group_rpl/consistent_members_that_must_prepare_transaction | YES | | memory/group_rpl/consistent_transactions | YES | | memory/group_rpl/consistent_transactions_prepared | YES | | memory/group_rpl/consistent_transactions_waiting | YES | | memory/group_rpl/consistent_transactions_delayed_view_change | YES | | memory/group_rpl/GCS_XCom::xcom_cache | YES | | memory/group_rpl/Gcs_message_data::m_buffer | YES | +-------------------------------------------------------------------+---------+
For more information on Performance Schema's memory instrumentation and events, see Section 29.12.20.10, “Memory Summary Tables”.
Performance Schema Group Replication instruments memory allocation
for Group Replication. The memory/group_rpl/
Performance Schema instrumentation contains the following
instruments:
write_set_encoded
: Memory allocated to
encode the write set before it is broadcast to the group
members.
Gcs_message_data::m_buffer
: Memory
allocated for the transaction data payload sent to the
network.
certification_data
: Memory allocated for
certification of incoming transactions.
certification_data_gc
: Memory allocated
for the GTID_EXECUTED sent by each member for garbage
collection.
certification_info
: Memory allocated for
storage of certification information allocated to resolve
conflicts between concurrent transactions.
transaction_data
: Memory allocated for
incoming transactions queued for the plugin pipeline.
message_service_received_message
: Memory
allocated to receiving messages from Group Replication
delivery message service.
sql_service_command_data
: Memory
allocated for processing the queue of internal SQL service
commands.
mysql_thread_queued_task
: Memory
allocated when a MySQL-thread dependent task is added to the
processing queue.
message_service_queue
: Memory allocated
for queued messages of the Group Replication delivery
message service.
GCS_XCom::xcom_cache
: Memory allocated to
XCOM ache for messaging and metadata exchanged between group
members as part of the consensus protocol.
consistent_members_that_must_prepare_transaction
:
Memory allocated to hold list of members preparing
transaction for Group Replication transaction consistency
guarantees.
consistent_transactions
: Memory allocated
to hold transaction and list of members that must prepare
that transaction for Group Replication transaction
consistency guarantees.
consistent_transactions_prepared
: Memory
allocated to hold list of transaction's info prepared for
the Group Replication Transaction Consistency Guarantees.
consistent_transactions_waiting
: Memory
allocated to hold information on a list of transactions
while preceding prepared transactions with consistency of
AFTER
and
BEFORE_AND_AFTER
are processed.
consistent_transactions_delayed_view_change
:
Memory allocated to hold list of view change events
(view_change_log_event
) delayed by
prepared consistent transactions waiting for prepare
acknowledgement.
group_member_info
: Memory allocated to
hold the group member properties. Properties such as
hostname, port, member weight and role, and so on.
The following instruments in the memory/sql/
grouping are also used to monitor Group Replication memory:
Log_event
: Memory allocated for encoding
transaction data into the binary log format; this is the same
format in which Group Replication transmits data.
write_set_extraction
: Memory allocated to
the transaction's generated write set before it is committed.
Gtid_set::to_string
: Memory allocated to
stored the string representation of a GTID set.
Gtid_set::Interval_chunk
: Memory allocated
to store the GTID object.