Decoding Syslog Server Messages SOW and High CPU Usage

Encountering unfamiliar syslog server messages can be unsettling, especially when coupled with performance issues like high CPU usage. This article delves into understanding syslog messages, particularly those resembling the “Syslog Server Messages Sow” you might be seeing, and how they relate to potential CPU spikes in your network devices. We will break down common syslog message components and explore troubleshooting steps to address high CPU utilization alongside these messages.

Understanding Syslog Messages: A Quick Primer

Syslog is a standard protocol for message logging. Network devices, servers, and other systems use syslog to send event messages to a central syslog server. These messages are invaluable for monitoring system health, security events, and troubleshooting operational issues. A typical syslog message contains several key pieces of information:

Timestamp: Indicates when the event occurred.
Facility: Categorizes the source of the message (e.g., User, Kernel, System).
Severity Level: Indicates the importance of the message (e.g., Debug, Notice, Error, Warning).
Hostname/IP Address: Identifies the device that sent the message.
Message ID: A unique identifier for the message type.
Message Text: The detailed description of the event.

Let’s look at an example similar to the messages provided:

2011-06-29 14:05:06User.Debug10.120.255.249Jun 29 14:04:08 uspinfo: %USER-7: Option S
2011-06-29 14:05:06User.Debug10.120.255.249Jun 29 14:04:08 uspinfo: %USER-7: uspinfo_handle_flow_command: Unknown option X ignoring it
2011-06-29 14:05:06User.Debug10.120.255.249Jun 29 14:04:08 uspinfo: %USER-7: cmd: flow
2011-06-29 14:05:06User.Debug10.120.255.249Jun 29 14:04:08 uspinfo: %USER-7: sub-cmd: show-session-summary

In these messages:

Timestamp: 2011-06-29 14:05:06 and Jun 29 14:04:08 (Note the slight discrepancy, likely due to different time formats or slight delays).
Facility: User.
Severity Level: Debug. Severity levels range from Emergency (most severe) to Debug (least severe, informational). Debug messages are typically very detailed and used for development and deep troubleshooting. A severity of 7 often corresponds to “Debug” level.
Hostname/IP Address: 10.120.255.249.
Message Source: uspinfo. This likely refers to a specific process or module within the device, possibly related to user services or session information.
Message Text: Provides details about the event, such as “Option S”, “Unknown option X ignoring it”, “cmd: flow”, and “sub-cmd: show-session-summary”.

Analyzing the Specific Syslog Messages and “sow”

The provided syslog messages originate from a device with the IP address 10.120.255.249 and are categorized under the User facility and Debug severity. They seem to be related to a process named uspinfo. The messages indicate that the uspinfo process is handling “flow” commands, specifically “show-session-summary”. The message “Unknown option X ignoring it” suggests that the process received a command with an option it doesn’t recognize and is proceeding without it.

The term “sow” in “syslog server messages sow” is not directly present in these logs, and might be a misinterpretation or a search term variation. However, when considering the context of syslog server messages, it’s crucial to look at the keywords within the messages themselves. In this case, terms like “uspinfo”, “flow”, “session-summary”, and “spu” are more relevant for understanding the issue.

The messages also include lines like:

pic_info_list_init_jssg_spu: PIC_INFO debug> Initializing spu listtype 25
pic_info_list_update_jssg_spu: PIC_INFO debug> Added entry - fpc 7, pic 0, name spu-14
flow_print_session_summary_output received ucast:1769, mcast:0, failed:0 active:1769 max:524288 spu-14

These lines suggest deeper internal operations related to “spu” (likely Service Processing Unit) and “pic” (likely Physical Interface Card). They seem to be debug information about session management and hardware components.

Connecting Syslog Messages to High CPU Usage

The crucial question is: are these syslog messages related to the observed high CPU usage? Debug messages themselves are generally low impact. However, the frequency and content of these messages can provide clues.

Here are potential scenarios linking these syslog messages to high CPU:

Excessive Logging: If the device is configured to log excessively at the debug level, the sheer volume of log processing and writing can consume CPU resources. While individual debug messages are light, a flood of them can become significant.
Underlying Issue Triggering Debug Logs: The debug messages might be a symptom of a more significant underlying issue. For example, if the uspinfo process is encountering errors or is being triggered very frequently due to network conditions or configuration problems, this could lead to both increased syslog messages and higher CPU usage.
Resource Intensive Operations: The “show-session-summary” command, and related operations like flow_print_session_info_in_xml, suggest the device is performing session monitoring or reporting tasks. If there’s a sudden surge in network traffic or sessions, these operations could become more CPU intensive, and the debug logs might be a side effect of this increased activity.
“watchdog: Time since last watchdog strob: 35” Message: The “watchdog” message “%KERN-5: watchdog: Time since last watchdog strob: 35” is more concerning. A watchdog timer is a hardware or software timer that is expected to be periodically reset (“strobed”) by the system. If the time since the last strobe is unusually long (35 in this case, the unit is not immediately clear but likely seconds), it could indicate that the system is becoming unresponsive or is under heavy load, preventing the watchdog from being reset in a timely manner. This message is a stronger indicator of potential CPU overload or system issues.

Troubleshooting Steps

To address the high CPU and investigate these syslog messages, consider the following steps:

Check Syslog Configuration: Verify the syslog configuration on the device. Is it set to log at a very verbose level (like debug) unnecessarily? Consider reducing the logging level to “Notice” or “Warning” for routine operation, and only enable debug logging when actively troubleshooting a specific issue.
Monitor CPU Usage Over Time: Track CPU usage trends. Is the high CPU constant, or does it spike at certain times? Correlate CPU spikes with the timestamps of the syslog messages to see if there’s a direct relationship.
Examine Network Traffic: Analyze network traffic patterns. Is there any unusual traffic surge or denial-of-service (DoS) attack that could be driving up session counts and CPU usage?
Investigate uspinfo Process: If possible, research the uspinfo process specific to your device’s operating system (likely Juniper Junos in this case based on the logs). Understand its function and whether its behavior is expected. Check for any known issues or bugs related to uspinfo and high CPU.
Check Device Resources: Examine other device resource utilization metrics besides CPU, such as memory, buffer usage, and interface statistics. Bottlenecks in other resources can sometimes indirectly lead to CPU pressure.
Firmware/Software Version: Ensure the device is running a stable and up-to-date firmware or software version. Software bugs can sometimes cause unexpected syslog messages and performance issues.
“show system processes extensive” (Juniper): If you are using a Juniper device, use the command show system processes extensive in the CLI to get a detailed view of process CPU and memory usage. This can help pinpoint if uspinfo or another process is the primary CPU consumer.
Contact Support: If you are unable to identify the root cause, and the high CPU and watchdog messages persist, consider contacting the vendor’s support (e.g., Juniper support) for assistance. Provide them with the syslog messages and CPU usage data for further analysis.

Conclusion

While debug syslog messages like those related to uspinfo are not inherently errors, their presence alongside high CPU usage, especially with watchdog messages, warrants investigation. By systematically analyzing the syslog messages, monitoring system resources, and following troubleshooting steps, you can gain a better understanding of the issue and take corrective actions to optimize device performance and resolve the underlying cause of the “syslog server messages sow” related concerns and high CPU utilization. Remember to prioritize reducing unnecessary debug logging and investigate potential network traffic or configuration issues that might be contributing to the problem.