Enable proper container shutdown by implementing trap SIGTERM signal handlers for graceful cleanup. Fix shell form CMD/ENTRYPOINT wrapping that prevents signal delivery, switch to exec form for direct signal forwarding, and add cleanup logic before exit. Verify containers exit within timeout using docker stop, prevent data corruption, and ensure resource cleanup. Essential for stateful applications, database connections, file handles, and zero-downtime deployments.

Kubernetes Pod Restart Troubleshooting: Fix web-app CrashLoopBackOff health Namespace. Diagnose and resolve web-app pod restart loops in health namespace where nginx serves port 80 / correctly but Kubernetes kills healthy containers. Master livenessProbe misconfiguration, CrashLoopBackOff diagnosis, pod events analysis, and probe timing optimization for stable web application deployments. Perfect for production troubleshooting, observability debugging, health check mastery, nginx stability, and Kubernetes reliability engineering.

Fix Kubernetes readiness probes: create health check scripts for Redis and MySQL dependencies, resolve container startup issues, and ensure pod readiness.

Definition for a binary tree node.

class TreeNode:

def init(self, val=0, left=None, right=None):

self.val = val

self.left = left

self.right = right

def invert_tree(root: Optional[TreeNode]) -> Optional[TreeNode]:
if not root:
return None

# Swap
root.left, root.right = root.right, root.left

# Recurse
invert_tree(root.left)
invert_tree(root.right)

return root

How to Retrieve and Order Product Data in SQL Based on Category and Price for an Interview

Objective

You are provided with a products table that includes columns id, name, category, and price. The task is to write an SQL query to fetch the name, category, and price of all pr...

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Connect to a SQLite database and compare customer records with a CSV file to identify which IDs exist in one source but not the other using Python.

Extract a proportionally representative sample from a dataset using pandas stratified sampling to ensure each region maintains its distribution in the sample.

Repartition a DataFrame to 8 partitions and output the resulting task count to understand how Spark maps partitions to parallel tasks.

WITH employee_agg AS (
SELECT
project_id,
COUNT(employee_id) AS total_employees,
COUNT(DISTINCT role) AS unique_roles
FROM {{ ref("employees") }}
GROUP BY project_id
),
equipment_agg AS (
SELECT
project_id,
SUM(cost) AS total_equipment_cost
FROM {{ ref("equipment") }}
GROUP BY project_id
)
SELECT
p.project_id,
p.project_name,
p.start_date,
p.end_date,
DATEDIFF('day', p.start_date, p.end_date) AS duration_days,
COALESCE(e.total_employees, 0) AS total_employees,
COALESCE(e.unique_roles, 0) AS unique_roles,
COALESCE(eq.total_equipment_cost, 0) AS total_equipment_cost
FROM {{ ref("projects") }} p
LEFT JOIN employee_agg e
ON p.project_id = e.project_id
LEFT JOIN equipment_agg eq
ON p.project_id = eq.project_id

WITH combined AS (
SELECT Country, Year, GDP FROM {{ ref("gdp_domestic") }}
UNION ALL
SELECT Country, Year, GDP FROM {{ ref("gdp_international") }}
),
with_lag AS (
SELECT
Country,
Year,
GDP,
LAG(GDP) OVER (PARTITION BY Country ORDER BY Year) AS prev_GDP
FROM combined
)
SELECT
Country,
Year,
ROUND(((GDP - prev_GDP) / prev_GDP) * 100, 2) AS GDP_growth_rate
FROM with_lag
ORDER BY Country ASC, Year ASC

SELECT
u.city,
COUNT(t.order_id) AS total_orders
FROM
trades t
INNER JOIN users u ON t.user_id = u.user_id
WHERE
t.status = 'Completed'
GROUP BY
u.city
ORDER BY
total_orders DESC
LIMIT
3;

WITH
ranked AS (
SELECT
ticker,
TO_CHAR(date, 'Mon-YYYY') AS month_year,
open,
ROW_NUMBER() OVER (
PARTITION BY
ticker
ORDER BY
open DESC
) AS high_rank,
ROW_NUMBER() OVER (
PARTITION BY
ticker
ORDER BY
open ASC
) AS low_rank
FROM
stock_prices
)
SELECT
h.ticker,
h.month_year AS highest_month,
h.open AS highest_open,
l.month_year AS lowest_month,
l.open AS lowest_open
FROM
ranked h
JOIN ranked l ON h.ticker = l.ticker
AND l.low_rank = 1
WHERE
h.high_rank = 1
ORDER BY
h.ticker;

Master JavaScript alert handling with Selenium. Learn prompt interaction, dynamic input processing, and comprehensive alert verification....

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