Always run the pg_upgrade binary of the new server, not the old one. pg_upgrade requires the specification of the old and new cluster's data and executable (bin) directories. You can also specify user and port values, and whether you want the data files linked or cloned instead of the default copy behavior.
A two-pinhole array coupled to a GXD camera was used to image simultaneously the plasma interaction region where turbulence was generated, with a different filter in front of each aperture. (A) Broadband x-ray emission filtered by 6.56-μm polyimide and (B) filtered by 2.36-μm vanadium foils at 25 ns after the initial drive lasers fired. The ratio of the x-ray emission in these two bands [polyimide/vanadium (Poly/V)] is shown in (C). In producing the image, regions within 20% of the background intensity were excluded, and a 50 μm (corresponding to the diameter of the pinholes) smoothing was applied. (D) Relation between the x-ray intensity ratio of polyimide to vanadium to the electron temperature of the plasma. The measured x-ray signal depends on the filter transmission (inset), the GXD camera response, and the plasma emission, which is a function of density and temperature. Since the wavelength dependence of the plasma emission is (mostly) insensitive to the density, the x-ray signal strengths from two different energy bands is a strong function of the temperature. When the temperature is larger than 450 eV, a one-to-one correspondence between the x-ray intensity ratio and the plasma temperature is thus obtained, in arbitrary units (a.u.).
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The optional FOR CHANNEL channel clause enables you to name which replication channel the statement applies to. Providing a FOR CHANNEL channel clause applies the CHANGE MASTER TO statement to a specific replication channel, and is used to add a new channel or modify an existing channel. For example, to add a new channel called channel2:
For some of the options of the CHANGE MASTER TO statement, you must issue a STOP SLAVE statement prior to issuing a CHANGE MASTER TO statement (and a START SLAVE statement afterwards). Sometimes, you only need to stop the replication SQL (applier) thread or the replication I/O (receiver) thread, not both:
When the applier thread is stopped, you can execute CHANGE MASTER TO using any combination that is otherwise allowed of RELAY_LOG_FILE, RELAY_LOG_POS, and MASTER_DELAY options, even if the replication receiver thread is running. No other options may be used with this statement when the receiver thread is running.
You can check the current state of the replication applier thread and replication receiver thread using SHOW SLAVE STATUS. Note that the Group Replication applier channel (group_replication_applier) has no receiver thread, only an applier thread.
CHANGE MASTER TO causes the previous values for MASTER_HOST, MASTER_PORT, MASTER_LOG_FILE, and MASTER_LOG_POS to be written to the error log, along with other information about the replica's state prior to execution.
If you are using statement-based replication and temporary tables, it is possible for a CHANGE MASTER TO statement following a STOP SLAVE statement to leave behind temporary tables on the replica. A warning (ER_WARN_OPEN_TEMP_TABLES_MUST_BE_ZERO) is issued whenever this occurs. You can avoid this in such cases by making sure that the value of the Replica_open_temp_tables or Slave_open_temp_tables system status variable is equal to 0 prior to executing such a CHANGE MASTER TO statement.
When using a multithreaded replica (replica_parallel_workers > 0 or slave_parallel_workers > 0), stopping the replica can cause gaps in the sequence of transactions that have been executed from the relay log, regardless of whether the replica was stopped intentionally or otherwise. When such gaps exist, issuing CHANGE MASTER TO fails. The solution in this situation is to issue START SLAVE UNTIL SQL_AFTER_MTS_GAPS which ensures that the gaps are closed. From MySQL 8.0.26, the process of checking for gaps in the sequence of transactions is skipped entirely when GTID-based replication and GTID auto-positioning are in use, because gaps in transactions can be resolved using GTID auto-positioning. In that situation, CHANGE MASTER TO can still be used.
Makes the replication channel assign a GTID to replicated transactions that do not have one, enabling replication from a source that does not use GTID-based replication, to a replica that does. For a multi-source replica, you can have a mix of channels that use ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS, and channels that do not. The default is OFF, meaning that the feature is not used.
LOCAL assigns a GTID including the replica's own UUID (the server_uuid setting). uuid assigns a GTID including the specified UUID, such as the server_uuid setting for the replication source server. Using a nonlocal UUID lets you differentiate between transactions that originated on the replica and transactions that originated on the source, and for a multi-source replica, between transactions that originated on different sources. The UUID you choose only has significance for the replica's own use. If any of the transactions sent by the source do have a GTID already, that GTID is retained.
Channels specific to Group Replication cannot use ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS, but an asynchronous replication channel for another source on a server instance that is a Group Replication group member can do so. In that case, do not specify the Group Replication group name as the UUID for creating the GTIDs.
To set ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS to LOCAL or uuid, the replica must have gtid_mode=ON set, and this cannot be changed afterwards. This option is for use with a source that has binary log file position based replication, so MASTER_AUTO_POSITION=1 cannot be set for the channel. Both the replication SQL thread and the replication I/O (receiver) thread must be stopped before setting this option.
A replica set up with ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS on any channel cannot be promoted to replace the replication source server in the event that a failover is required, and a backup taken from the replica cannot be used to restore the replication source server. The same restriction applies to replacing or restoring other replicas that use ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS on any channel.
This option applies to replicas that authenticate with the caching_sha2_password authentication plugin. For connections by accounts that authenticate using this plugin, the source does not send the public key unless requested, so it must be requested or specified in the client. If MASTER_PUBLIC_KEY_PATH is given and specifies a valid public key file, it takes precedence over GET_MASTER_PUBLIC_KEY. If you are using a replication user account that authenticates with the caching_sha2_password plugin (which is the default from MySQL 8.0), and you are not using a secure connection, you must specify either this option or the MASTER_PUBLIC_KEY_PATH option to provide the RSA public key to the replica.
Stops the replication channel persisting file names and file positions in the replication metadata repositories. GTID_ONLY is available as of MySQL 8.0.27. The GTID_ONLY option is disabled by default for asynchronous replication channels, but it is enabled by default for Group Replication channels, and it cannot be disabled for them.
For replication channels with this setting, in-memory file positions are still tracked, and file positions can still be observed for debugging purposes in error messages and through interfaces such as SHOW REPLICA STATUS statements (where they are shown as being invalid if they are out of date). However, the writes and reads required to persist and check the file positions are avoided in situations where GTID-based replication does not actually require them, including the transaction queuing and application process.
This option can be used only if both the replication SQL (applier) thread and replication I/O (receiver) thread are stopped. To set GTID_ONLY = 1 for a replication channel, GTIDs must be in use on the server (gtid_mode = ON), and row-based binary logging must be in use on the source (statement-based replication is not supported). The options REQUIRE_ROW_FORMAT = 1 and SOURCE_AUTO_POSITION = 1 must be set for the replication channel.
When GTID_ONLY = 1 is set, the replica uses replica_parallel_workers=1 if that system variable is set to zero for the server, so it is always technically a multi-threaded applier. This is because a multi-threaded applier uses saved positions rather than the replication metadata repositories to locate the start of a transaction that it needs to reapply.
If you disable GTID_ONLY after setting it, the existing relay logs are deleted and the existing known binary log file positions are persisted, even if they are stale. The file positions for the binary log and relay log in the replication metadata repositories might be invalid, and a warning is returned if this is the case. Provided that SOURCE_AUTO_POSITION is still enabled, GTID auto-positioning is used to provide the correct positioning.
If you also disable SOURCE_AUTO_POSITION, the file positions for the binary log and relay log in the replication metadata repositories are used for positioning if they are valid. If they are marked as invalid, you must provide a valid binary log file name and position (SOURCE_LOG_FILE and SOURCE_LOG_POS). If you also provide a relay log file name and position (RELAY_LOG_FILE and RELAY_LOG_POS), the relay logs are preserved and the applier position is set to the stated position. GTID auto-skip ensures that any transactions already applied are skipped even if the eventual applier position is not correct.
Makes the replica ignore events originating from the specified servers. The option takes a comma-separated list of 0 or more server IDs. Log rotation and deletion events from the servers are not ignored, and are recorded in the relay log. 2ff7e9595c
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