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Memory Usage Patterns¶

Use this query to spot memory pressure trends, allocation failures, and likely OOM indicators from application console output.

Data Source¶

Table	Schema Note
`ContainerAppConsoleLogs_CL`	Legacy schema. If empty, try `ContainerAppConsoleLogs` (non-`_CL`).

Query Pipeline¶

flowchart LR
    A[Filter by app and time window] --> B[Match memory and OOM terms] --> C[Classify signal type] --> D[Summarize by time bin and revision]

Query¶

let AppName = "my-container-app";
let Window = 24h;
ContainerAppConsoleLogs_CL
| where ContainerAppName_s == AppName and TimeGenerated >= ago(Window)
| where Log_s has_any ("oom", "out of memory", "memoryerror", "heap out of memory", "cannot allocate memory", "memory limit")
| extend Signal = case(
    Log_s has_any ("oomkilled", "out of memory", "oom-kill", "killed process"), "OOM indicator",
    Log_s has_any ("heap out of memory", "memoryerror", "cannot allocate memory"), "Allocation failure",
    Log_s has_any ("memory limit", "high memory", "max_old_space_size"), "Memory pressure warning",
    "Other memory signal"
)
| summarize events=count(), sampleLog=take_any(Log_s) by bin(TimeGenerated, 15m), RevisionName_s, Stream_s, Signal
| order by TimeGenerated desc, events desc

Example Output¶

TimeGenerated	RevisionName_s	Stream_s	Signal	events	sampleLog
2026-04-04T11:45:00.000Z	ca-myapp--0000003	stderr	OOM indicator	4	FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory
2026-04-04T11:30:00.000Z	ca-myapp--0000003	stderr	Allocation failure	2	MemoryError: cannot allocate 67108864 bytes
2026-04-04T11:15:00.000Z	ca-myapp--0000002	stdout	Memory pressure warning	6	warning: process rss=472MiB approaching memory limit=512MiB

Interpretation Notes¶

Repeated Memory pressure warning bins often appear before harder failures in later bins.
OOM indicator on stderr usually means the process hit a hard limit or was terminated after exhausting memory.
Normal pattern: occasional memory diagnostics, not sustained warning or OOM clusters.

Limitations¶

Depends on the application or runtime emitting memory-related text to stdout/stderr.
This query infers memory issues from console messages and does not measure actual container memory metrics.

See Also¶