Note
This view was introduced in OceanBase Database V4.2.1.
Purpose
This view displays diagnostic information about full-link trace.
Columns
| Column |
Type |
Nullable? |
Description |
| TENANT_ID |
bigint(20) |
NO |
The ID of the tenant. Other values: the ID of a user tenant or a meta tenant. |
| TYPE |
varchar(16) |
NO |
The monitoring level of the diagnostic information. module/action level: the diagnostic information is monitored at the module and action levels.client_identifier level: the diagnostic information is monitored at the client identifier level. |
| TENANT_NAME |
varchar(128) |
NO |
The name of the tenant. |
| MODULE_NAME |
varchar(4096) |
NO |
The name of the module. |
| ACTION_NAME |
varchar(4096) |
NO |
The name of the action. |
| CLIENT_IDENTIFIER |
varchar(65) |
NO |
The name of the client identifier. |
| LEVEL |
bigint(20) |
NO |
The full-link trace monitoring level of the session. For example, 1 indicates that the diagnostic information with level 1 is traced. |
| SAMPLE_PERCENTAGE |
bigint(20) |
NO |
The full-link trace sampling frequency of the session. For example, 50 indicates that the diagnostic information is sampled with a probability of 50%. |
| RECORD_POLICY |
varchar(32) |
NO |
The full-link trace recording strategy of the session. The following three strategies are supported:
- ALL: trace points of all diagnostic information that are traced by full-link trace and whose sampling is enabled are printed to the log file. The trace points are printed to the log file when each span ends.
- ONLY_SLOW_QUERY: trace points of all diagnostic information that are traced by full-link trace and whose sampling is enabled are printed to the log file if the request is a slow query. Otherwise, the trace points are discarded. For this printing strategy, the trace log is printed to the log file after the request is determined to be a slow query. In a proxy, for a root span, which is a transaction-level span, the root span is printed to the log file when a slow query is detected.
- SAMPLE_AND_SLOW_QUERY: trace points of all diagnostic information that are traced by full-link trace and whose sampling is enabled are printed to the log file if they meet the following conditions:
- When the
_print_sample_ppm hidden parameter is used for sampling at a probability of 1 per ten thousand, the trace points are printed to the log file only if the sampling result is selected.
- The trace points meet the printing conditions of the ONLY_SLOW_QUERY mode.
In this mode, the trace points are not printed to the log file when each span ends. If condition 1 is met, the trace points are marked as forced to be printed in the client, and the information is passed to the subsequent link component. If condition 2 is met, the trace points are printed to the log file when the request is determined to be a slow query.
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