Chapter 308: Ports and Thresholds

The Enter key was pressed. Three lines of diagnostic logs scrolled across the terminal screen. PING 10.0.4.12: Request timed out. TCP SYN to 10.0.4.12:6379 blocked. Firewall policy: DROP all non-whitelist. Lin Chen stared at the last line, his breathing steady. The closed network was more airtight than anticipated. The path for dynamic port allocation was completely sealed off; Redis’s default port 6379 had become a dead end. He pulled up the local routing table, his fingers flying across the keyboard. iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE. He masqueraded the outbound traffic as the committee-approved ports 8080 and 443, setting up a layer of local port mapping. Su Man watched the data stream on the screen beside him, not asking if it would work. She knew it was pointless to ask.

A sudden twitch ran through the calf muscle of his left leg. Like a rusted spring being forcibly stretched. Lin Chen’s right hand instinctively gripped the edge of the desk, his knuckles turning white. He didn’t look down, merely shifting his center of gravity half an inch to the right to let the chair back bear more of the weight. The pain was a clear signal, but it required no action. He categorized it as “hardware aging”; as long as it didn’t trigger a system-level crash, it could be suspended. From the earthen stove in Qingshi Village to the server rooms in the provincial capital, and then to the office towers in first-tier cities, he had long grown accustomed to treating pain as a resident process running in the background. No interruptions, no extra attention allocated. As long as the main thread kept running, the system wouldn’t crash.

“Capture packets,” he said quietly.

Waveforms popped up on the Wireshark interface. The originally red dropped packets gradually turned into green ACKs. Latency dropped from timeout to 1.4 seconds, then to 1.1 seconds. Lin Chen typed the final configuration command into the terminal and restarted the Redis service. A line flashed across the screen: Ready to accept connections.

“It’s through,” Su Man said, glancing at the wall clock. 8:52.

Lin Chen closed the terminal window and pushed the spare switch back to the bottom of the equipment case. He stood up. A dull ache shot through his left foot as it hit the floor; his gait was slightly uneven, but his rhythm remained unbroken. He walked to the head of the conference table and connected the demonstration laptop to the projector. The screen lit up, displaying the topology of the data pipeline. On the left was the raw data ingress, in the middle were the desensitization and validation nodes, and on the right was the output queue. Sampling rate set at 1.2 seconds. Circuit breaker threshold at 85%. All parameters were written on the whiteboard, nothing hidden, nothing embellished.

9:00 sharp. The conference room door was pushed open.

Three people walked in. In the middle was Deputy Director Zhou of the Ethics Committee, his hair graying, holding a black folder. To his left was an auditor from the Health Commission, wearing glasses, his expression stern. To his right was a representative sent by Zhao Qiming, surnamed Chen, in his early thirties, wearing a well-tailored suit, spinning a metal fountain pen in his hand. Without pleasantries, the three took their seats. Director Zhou opened the folder, his gaze sweeping over the parameters on the whiteboard before settling on Lin Chen.

“Begin.”

Lin Chen nodded. His finger pressed Enter.

The demonstration pipeline started. Data streams began scrolling across the screen. Raw samples entered the pipeline, passed through regex matching, hash-based desensitization, and outlier filtering, before finally landing in the output queue. The latency curve was plotted in real-time on the right. 1.15 seconds. 1.12 seconds. 1.18 seconds. The fluctuation range was kept within 0.1 seconds. Su Man slid three compliance boundary documents toward Director Zhou, her voice steady: “All desensitization rules comply with Article 28 of the Personal Information Protection Law. The audit trail is complete and tamper-proof. Anomalous samples have been isolated and will not enter downstream models.”

Director Zhou looked down, flipping through the documents, occasionally underlining key points with his pen tip. The auditor stared at the latency curve on the screen, saying nothing. Representative Chen stopped spinning his pen and leaned forward slightly.

“A sampling rate of 1.2 seconds,” Representative Chen spoke, his tone flat. “This isn’t real-time. It’s batch processing with a cache layer. If concurrency spikes, Redis’s memory queue will overflow. Your architecture won’t hold up in a production environment.”

Lin Chen didn’t immediately rebut. He pulled up the backend monitoring dashboard and switched to the resource utilization view. CPU usage at 42%, memory at 68%, network I/O stable.

“The current architecture is pseudo-real-time,” Lin Chen’s voice was low, but every word was clear. “The core validation logic runs offline, while the sampling queue uses caching. This is the balance point between cost and compliance. What the committee wants is a traceable audit trail, not millisecond-level response. A 1.2-second delay fully meets the business threshold in a medical data desensitization scenario. If we force true real-time, memory costs will triple, and it won’t pass the 500MB hard threshold limit of the legacy system.”

Representative Chen smiled, tapping his pen tip lightly twice on the table. “Capital doesn’t fund pseudo-real-time. Capital cares about scalability. You can run the demo now because the data volume is small. Once you connect to the provincial hospital’s full-scale interface, your circuit breaker will directly trigger a degradation. At that point, the latency won’t be 1.2 seconds. It’ll be 12 seconds. Or even a disconnect.”

“That’s why the circuit breaker threshold is set at 85%,” Lin Chen pulled up another chart, a simulated stress test curve. “Once the threshold is exceeded, the system automatically switches to offline validation. No data is lost, only latency increases. This is a degradation strategy, not an architectural flaw. The demo proves the logical closed loop, not the production capacity ceiling. Capacity requires stacking computing power, and computing power requires capital.”

The room fell silent for a few seconds. Director Zhou closed the folder, took off his glasses, and wiped them. “The logic holds. But audits demand certainty. Has your degradation strategy undergone third-party stress testing?”

“No,” Lin Chen answered bluntly. “The budget doesn’t support it. But we have complete error logs and rollback scripts. Every anomaly is recorded. It can be reproduced on the spot.”

Director Zhou looked at him, not pressing further. He signed the document and passed it to the auditor. After verifying it, the auditor also signed. Representative Chen didn’t pick up a pen, merely slipping his fountain pen into his pocket. “The demo passes. But a clause will be added: within seventy-two hours, provide a production-grade stress test report. Otherwise, the valuation adjustment liquidation will proceed as originally planned.”

Lin Chen nodded. “Understood.”

9:40. The meeting ended. The three stood up and left. After the door closed, only the low hum of the server fans remained in the conference room.

Su Man began packing up the documents. Lin Chen crouched down, unplugged the network cables, and powered off the equipment. A sharp sting shot through his left foot as it bent; his movement paused for a fraction of a second before returning to normal. He packed the equipment back into the case piece by piece, attaching labels. His movements were mechanical, but precise.

“We passed,” Su Man said, stuffing the last document into the folder and zipping it up.

“Just the first gate,” Lin Chen said, standing up and slinging his backpack over his shoulder. The numbness in his left leg had already spread to the root of his thigh, feeling like it was filled with lead. He steadied himself against the table edge, his breathing slightly heavier, but he didn’t complain.

The two walked out of the building. The morning fog had already lifted, the sunlight glaring. Only a few early-arriving cars sat in the parking lot. Lin Chen leaned against a pillar, fished out painkillers from his pocket, and dry-swallowed them. The pill caught in his throat; he took a sip of cold water from his thermos to barely force it down.

His phone vibrated.

Not a reply from the committee. It was a WeChat message from Zhao Qiming’s assistant. Attached was a draft of the valuation adjustment agreement. The body contained only one line: Demo passed. But capital doesn't fund pseudo-real-time. Within seventy-two hours, provide stress test data for true concurrency, or the valuation adjustment liquidation will proceed as planned.

Lin Chen stared at the screen. Seventy-two hours. True concurrency. Production-grade stress testing.

He looked up at Su Man. “The old test machine’s hard drive won’t handle continuous read/write operations. The mechanical drive will just lock up.”

Su Man paused for a moment, then immediately understood. “I’ll go to the electronics market. Look for enterprise-grade SSDs. If the budget is tight, I’ll get used pull drives.”

“Get two. Set up RAID 0,” Lin Chen slipped his phone back into his pocket, his fingers tapping lightly twice against his trouser seam, as if mentally calculating time. “All-nighter tonight. I’ll write the stress test scripts. You’ll handle monitoring. Use Locust for data injection, scaling concurrency from one thousand to fifty thousand. Record IOPS and latency distribution.”

Su Man nodded and turned toward the parking lot. Lin Chen didn’t move. He leaned against the pillar, closing his eyes. There was no anxiety in his mind, only clear steps: procurement, assembly, environment deployment, script writing, stress injection, data collection. Every step had a fault-tolerance plan. Every step had a fallback path. He didn’t need a miracle; he just needed to fill in the known variables.

He unzipped his backpack, pulled out the worn-edge notebook he used for tracking errors, and flipped to a fresh page. He wrote: True concurrency stress test. RAID 0 array. Enterprise SSD. 72-hour deadline.

The pen tip paused. He added another line: Capital demands certainty. We provide the trail.

The rumble of a truck’s engine sounded in the distance. The city was waking up. Lin Chen opened his eyes and stepped toward the parking lot. His left foot still felt heavy as it hit the ground, but his rhythm remained unbroken. The next step was procurement.