filerep_*

The filerep* tables store high-availability file replication process information for a Greenplum Database instance. There are three filerep tables, all having the same columns:

  • filerep_now is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. Current file replication data is stored in filerep_now during the period between data collection from the Command Center agents and automatic commitment to the filerep_history table.
  • filerep_tail is an external table whose data files are stored in $MASTER_DATA_DIRECTORY/gpperfmon/data. This is a transitional table for file replication data that has been cleared fromfilerep_now but has not yet been committed to filerep_history. It typically only contains a few minutes worth of data.
  • filerep_history is a regular table that stores historical database-wide file replication data. It is pre-partitioned into monthly partitions. Partitions are automatically added in two month increments as needed. Administrators must drop old partitions for the months that are no longer needed.
Column Type Description
ctime timestamp Time this row was created.
primary_measurement_microsec bigint

The length of time over which primary metrics (contained in UDP messages) were gathered.

mirror_measurement_microsec  bigint The length of time over which mirror metrics (contained in UDP messages) were gathered.
primary_hostname varchar(64) The name of the primary host.
primary_port int The port number of the primary host.
mirror_hostname varchar(64)  The name of the mirror host.
mirror_port int The port number of the mirror host.
primary_write_syscall_bytes_avg bigint The average amount of data written to disk on the primary for write system calls per interval.
primary_write_syscall_byte_max  bigint The maximum amount of data written to disk on the primary for write system calls per interval.
primary_write_syscall_microsecs_avg  bigint

The average time required for a write system call to write data to disk on the primary per interval.

primary_write_syscall_microsecs_max bigint The maximum time required for a write system call to write data to disk on the primary per interval.
primary_write_syscall_per_sec double precision

The number of write system calls on the primary per second. It reflects only the time to queue the write to disk in memory.

primary_fsync_syscall_microsec_avg bigint

The average amount of time required for a file sync system call to write data to disk on the primary per interval.

primary_fsync_syscall_microsec_max bigint The maximum amount of time required for a file sync system call to write data to disk on the primary per interval.
primary_fsync_syscall_per_sec double precision The number of file sync system calls on the primary per second. Unlike write system calls which return immediately after the data is posted/queued, file sync system calls wait for all outstanding writes to be written to disk. File sync system call values in this column reflect actual disk access times for potentially large amounts of data.
primary_write_shmem_bytes_avg bigint The average amount of data written to shared memory on the primary per interval.
primary_write_shmem_bytes_max bigint The maximum amount of data written to shared memory on the primary per interval.
primary_write_shmem_microsec_avg bigint

The average amount of time required to write data to shared memory on the primary per interval.

primary_write_shmem_microsec_max bigint The maximum amount of time required to write data to shared memory on the primary per interval.
primary_write_shmem_per_sec double precision

The number of writes to shared memory on the primary per second.

primary_fsync_shmem_microsec_avg bigint

The average amount of time required by the file sync system call to write data to shared memory on the primary per interval.

primary_fsync_shmem_microsec_max bigint The maximum amount of time required by the file sync system call to write data to shared memory on the primary per interval.
primary_fsync_shmem_per_sec double precision The number of file sync calls to shared memory on the primary per second. File sync system call values in this column reflect actual disk access times for potentially large amounts of data.
primary_write_shmem_per_sec double precision

The number of writes to shared memory on the primary per second.

primary_fsync_shmem_microsec_avg bigint

The average amount of time required by the file sync system call to write data to shared memory on the primary per interval.

primary_fsync_shmem_microsec_max bigint The maximum amount of time required by the file sync system call to write data to shared memory on the primary per interval.
primary_fsync_shmem_per_sec double precision The number of file sync calls to shared memory on the primary per second. File sync system call values in this column reflect actual disk access times for potentially large amounts of data.
primary_roundtrip_fsync_msg_microsec_avg bigint

The average amount of time required for a roundtrip file sync between the primary and the mirror per interval. This includes:

  1. The queuing of a file sync message from the primary to the mirror.
  2. The message traversing the network.
  3. The execution of the file sync by the mirror.
  4. The file sync acknowledgement traversing the network back to the primary.
primary_roundtrip_fsync_msg_microsec_max bigint

The maximum amount of time required for a roundtrip file sync between the primary and the mirror per interval. This includes:

  1. The queuing of a file sync message from the primary to the mirror.
  2. The message traversing the network.
  3. The execution of the file sync by the mirror.
  4. The file sync acknowledgement traversing the network back to the primary.
primary_roundtrip_fsync_msg_per_sec double precision

The number of roundtrip file syncs per second.

primary_roundtrip_test_msg_microsec_avg bigint

The average amount of time required for a roundtrip test message between the primary and the mirror to complete per interval. This is similar to primary_roundtrip_fsync_msg_microsec_avg, except it does not include a disk access component. Because of this, this is a useful metric that shows the average amount of network delay in the file replication process.

primary_roundtrip_test_msg_microsec_max bigint

The maximum amount of time required for a roundtrip test message between the primary and the mirror to complete per interval. This is similar to primary_roundtrip_fsync_msg_microsec_max, except it does not include a disk access component. Because of this, this is a useful metric that shows the maximum amount of network delay in the file replication process.

primary_roundtrip_test_msg_per_sec double precision

The number of roundtrip file syncs per second. This is similar to primary_roundtrip_fsync_msg_per_sec, except it does not include a disk access component. As such, this is a useful metric that shows the amount of network delay in the file replication process.

Note that test messages typically occur once per minute, so it is common to see a value of “0” for time periods not containing a test message.

mirror_write_syscall_size_avg bigint The average amount of data written to disk on the mirror for write system calls per interval.
mirror_write_syscall_size_max bigint The maximum amount of data written to disk on the mirror for write system calls per interval.
mirror_write_syscall_microsec_avg bigint

The average time required for a write system call to write data to disk on the mirror per interval.

mirror_write_syscall_microsec_max bigint The maximum time required for a write system call to write data to disk on the mirror per interval.
primary_roundtrip_test_msg_per_sec double precision

The number of roundtrip file syncs per second. This is similar to primary_roundtrip_fsync_msg_per_sec, except it does not include a disk access component. As such, this is a useful metric that shows the amount of network delay in the file replication process.

Note that test messages typically occur once per minute, so it is common to see a value of “0” for time periods not containing a test message.

mirror_write_syscall_size_avg bigint The average amount of data written to disk on the mirror for write system calls per interval.
mirror_write_syscall_size_max bigint The maximum amount of data written to disk on the mirror for write system calls per interval.
mirror_write_syscall_microsec_avg bigint

The average time required for a write system call to write data to disk on the mirror per interval.