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After 25 incidents occur for the same problem key in one day, subsequent incidents for this problem key are flood-controlled. Normal recording of incidents for that problem key begins again on the next day.

In addition, after 50 incidents for the same problem key occur in one hour, or 250 incidents for the same problem key occur in one day, subsequent incidents for this problem key are not recorded at all in the ADR. In these cases, the database writes a message to the alert log indicating that no further incidents will be recorded. As long as incidents continue to be generated for this problem key, this message is added to the alert log every ten minutes until the hour or the day expires. Upon expiration of the hour or day, normal recording of incidents for that problem key begins again.

7.1.2.3 Related Problems Across the Topology

For any problem identified in a database instance, the diagnosability framework can identify related problems across the topology of your Oracle Database installation.

In a single instance environment, a related problem could be identified in the local Oracle ASM instance. In an Oracle RAC environment, a related problem could be identified in any database instance or Oracle ASM instance on any other node. When investigating problems, you are able to view and gather information on any related problems.

A problem is related to the original problem if it occurs within a designated time period or shares the same execution context identifier. An execution context identifier (ECID) is a globally unique identifier used to tag and track a single call through the Oracle software stack, for example, a call to Oracle Fusion Middleware that then calls into Oracle Database to retrieve data. The ECID is typically generated in the middle tier and is passed to the database as an Oracle Call Interface (OCI) attribute. When a single call has failures on multiple tiers of the Oracle software stack, problems that are generated are tagged with the same ECID so that they can be correlated. You can then determine the tier on which the originating problem occurred.

7.1.3 Fault Diagnosability Infrastructure Components

The fault diagnosability infrastructure consists of several components, including the Automatic Diagnostic Repository (ADR), various logs, trace files, the Enterprise Manager Support Workbench, and the ADRCI Command-Line Utility.

Automatic Diagnostic Repository (ADR)

The ADR is a file-based repository for database diagnostic data such as traces, dumps. the alert log, health monitor reports, and more. It has a unified directory structure across multiple instances and multiple products.

Alert Log The alert log is an XML file that is a chronological log of messages and errors. Attention Log

The attention log is a structured, externally modifiable file that contains information about

critical and highly visible database events. Use the attention log to quickly access information about critical events that need action.

Trace Files, Dumps, and Core Files

Trace files, dumps, and core files contain diagnostic data that are used to investigate problems. They are stored in the ADR. DDL Log

The data definition language (DDL) log is a file that has the same format and basic

behavior as the alert log, but it only contains the DDL statements issued by the database.
Debug Log An Oracle Database component can detect conditions, states, or events that are

unusual, but which do not inhibit correct operation of the detecting component. The component can issue a warning about these conditions, states, or events. The debug log is a file that records these warnings.

Other ADR Contents

In addition to files mentioned in the previous sections, the ADR contains health

monitor reports, data repair records, SQL test cases, incident packages, and more. These components are described later in the chapter.

Enterprise Manager Support Workbench

The Enterprise Manager Support Workbench (Support Workbench) is a facility that enables you to investigate, report, and in some cases, repair problems (critical errors), all with an easy-to-use graphical interface.

ADRCI Command-Line Utility

The ADR Command Interpreter (ADRCI) is a utility that enables you to investigate problems, view health check reports, and package first-failure diagnostic data, all within a command-line environment.

7.1.3.1 Automatic Diagnostic Repository (ADR)

The ADR is a file-based repository for database diagnostic data such as traces, dumps, the alert log, health monitor reports, and more. It has a unified directory structure across multiple instances and multiple products.

The database, Oracle Automatic Storage Management (Oracle ASM), the listener, Oracle Clusterware, and other Oracle products or components store all diagnostic data in the ADR. Each instance of each product stores diagnostic data underneath its own home directory within the ADR. For example, in an Oracle Real Application Clusters environment with shared storage and Oracle ASM, each database instance and each Oracle ASM instance has an ADR home directory. ADR's unified directory structure. consistent diagnostic data formats across products and instances, and a unified set of tools enable customers and Oracle Support to correlate and analyze diagnostic data across multiple instances. With Oracle Clusterware, each host node in the cluster has an ADR home directory.

Note:

Because all diagnostic data, including the alert log, are stored in the ADR, the initialization parameters BACKGROUND DUMP DEST and USER DUMP DEST are deprecated. They are replaced by the initialization parameter DIAGNOSTIC DEST, which identifies the location of the ADR.

Related Topics

Structure, Contents, and Location of the Automatic Diagnostic Repository The Automatic Diagnostic Repository (ADR) is a directory structure that is stored outside of the database. It is therefore available for problem diagnosis when the database is down.
Action

Contents of the Attention Log

The following is an example of an attention log message that needs immediate action.

IMMEDIATE "PMON (ospid: 3565): terminating the instance due to ORA

error 822"

CAUSE: "PMON detected fatal background process death" ACTION: "Termination of fatal background is not recommended,

Investigate cause of process termination"

CLASS : CDB-INSTANCE/ CDB ADMIN / ERROR / DBAL-35782660 TIME: 2020-03-28T14:15:16.159-07:00

INFO: "Some additional data on error PMON error"

Related Topics

Viewing Attention Log Information Access information stored in the attention log either by opening the file with any text editor or by querying the V$DIAG_ALERT EXT view.

7.1.3.4 Trace Files, Dumps, and Core Files

Trace files, dumps, and core files contain diagnostic data that are used to investigate problems. They are stored in the ADR.

Trace Files

Each server and background process can write to an associated trace file. Trace files are updated periodically over the life of the process and can contain information on the process environment, status, activities, and errors. In addition, when a process detects a critical error, it writes information about the error to its trace file.

Dumps

A dump is a specific type of trace file. A dump is typically a one-time output of diagnostic data in response to an event (such as an incident), whereas a trace tends to be continuous output of diagnostic data.

Core Files

A core file contains a memory dump, in an all-binary, port-specific format.

7.1.3.4.1 Trace Files

Each server and background process can write to an associated trace file. Trace files are updated periodically over the life of the process and can contain information on the process environment, status, activities, and errors. In addition, when a process detects a critical error, it writes information about the error to its trace file.

The SQL trace facility also creates trace files, which provide performance information on individual SQL statements. You can enable SQL tracing for a session or an instance.

Trace file names are platform-dependent. Typically, database background process trace file names contain the Oracle SID, the background process name, and the operating system process number, while server process trace file names contain the