Chapter 211: Cold Machines and Thresholds

The ride-hailing car left the Fourth Ring Road, and the asphalt gradually grew rougher. Outside the window, the dense rows of office towers gave way to squat factory buildings, dusty greenbelts, and the occasional freight truck flashing past. Lin Chen leaned back in the rear seat, his left foot resting on the piece of cardboard he had brought with him, the sole of his shoe suspended in midair to avoid any unnecessary friction. The driver was moving fast. Now and then the chassis rolled over a speed bump, and each jolt made the muscles in his calf tighten. He closed his eyes and ran through the deployment process in his head: SSH connection, pull the image, mount the data volume, start the container, monitor the logs. V3.0’s exception handling already had three layers added to it, but the node Old Zhao had provided used an E5 processor from two years ago, with only 32 gigs of memory. The concurrency had to be kept down to four. Anything higher and an OOM would kill the process outright. He could not leave it to luck. He could only calculate his margins.

Forty minutes later, the car stopped at the gate of an inconspicuous complex in the western suburbs. Beside the iron gate hung a brass plaque reading “XX Cloud Computing Data Center.” Its paint was already peeling, the edges curling up. Lin Chen scanned to pay and pushed open the door. The early autumn wind carried the dry chill peculiar to server rooms straight into his face, mixed with the faint rumble of a diesel generator. Using the folding umbrella he had brought as a cane, he made his way into the lobby step by step. No one was at the front desk. Only the surveillance screens on the wall flickered with a dim blue glow, and behind the glass of the security booth a few cases of bottled water were stacked up. He dialed the number Old Zhao had left him.

“You there?” The voice on the other end was noisy, with the dense whir of fans in the background. “Third floor, Zone B, cabinet 307. I sent the password to your phone. Swipe yourself in. Don’t touch any other equipment. The deposit goes through WeChat. Send me screenshots once the data finishes running, and I’ll settle the balance. You know the rules. Machines don’t wait for people.”

“Understood.” Lin Chen hung up and went upstairs as instructed. The corridor was laid with antistatic flooring that gave slightly underfoot, each step accompanied by the faint sound of static clinging and releasing. The indicator lights on cabinet 307 were packed tight, red and green interwoven like a miniature, silent starfield. He found the reserved network port, plugged in the cable, and opened his laptop. The terminal window popped up. He entered the IP, port, and key. Connection successful. He uploaded the Docker image and typed out docker run -d --name cleaner_v3 -v /data:/app/data cleaner:latest. He hit Enter. The progress bar began to roll.

He pulled over a folding chair and sat down, keeping his left foot off the ground. Logs began flooding the screen: [INFO] Loading xlrd module... [INFO] Chunk size set to 5000... [INFO] Starting batch 1/8... In the first minute, CPU usage jumped to 65 percent. In the second, the memory graph rose steadily. Lin Chen stared at the screen, his fingers tapping unconsciously on his knee. He needed to confirm two things: first, whether chunked reads had truly solved the lag caused by large files; second, whether the fallback replacement for uncommon characters would slow overall throughput. The cold air from the server room AC blew straight at his back, yet his ankle felt faintly hot. The numb area in his left foot was spreading toward his calf, as if a thin cord were slowly tightening. He stood up, bracing himself on the edge of the cabinet, and began ankle pumps. Toes up, press down, twenty repetitions. Blood flow returned, bringing the prickling pain into sharp relief for a moment before it sank back into numbness. He could not sit too long, and he could not stand too long either. Time had been sliced into fifteen-minute segments, and every segment had to produce results.

Twenty minutes later, Batch 3 finished. A warning appeared in the log: [WARNING] Encoding mismatch at row 14203, fallback applied. Lin Chen let out a breath. The fallback mechanism had worked. No crash. But the CPU temperature monitor showed the cores beginning to throttle. He pulled up the resource panel and found that xlrd was generating a buildup of temporary cache while parsing columns with mixed encodings. He immediately opened the editor, modified the configuration directly inside the container, lowered the cache threshold from the default 10 MB to 4 MB, and forced garbage collection. Save. Restart the process. The progress bar stalled briefly, then started moving again.

At the forty-minute mark, Batch 6 was complete. The progress bar had reached 75 percent. He opened Excel and compared the raw sample Old Zhao had given him with the cleaned output. Fields aligned. Null values removed. Date formats unified. The error rate was controlled within 0.3 percent. It met the delivery standard. He took screenshots, packaged them together with the runtime logs, and sent them to Old Zhao.

His phone vibrated. Old Zhao replied: It ran through. Final payment is twelve hundred. I’ll transfer it to your card. There are two more batches next Monday, bigger volume and messier formats. Can you take them?

Lin Chen looked at the screen. Twelve hundred. Added to the earlier deposit and what he could juggle around the hospital loan, his cash flow could just barely hold until next week. But “bigger volume and messier formats” meant V3.0’s fault-tolerance threshold would have to be pushed even lower. He needed to rewrite the parser and replace the hard-coded rules with a configurable YAML file. Otherwise, the next batch run might get stuck on nonstandard fields, and the time cost of rework would punch straight through the limits of what his body could bear.

He typed back: I can take them. But settlement has to be based on the number of valid cleaned records. Any portion where the raw data has a missing-rate above 15 percent is not billable. I’ll upgrade the script and compress batch runtime to within three hours. If the script is interrupted because of the raw data format, the responsibility is not on my side.

He hit send. Leaning against the cabinet, he listened to the roar of the fans. Old Zhao did not reply at once. The server room was kept at a constant twenty-two degrees, but he felt cold. He knew he was probing the boundary. Old Zhao was a middleman who resold computing power and took outsourced jobs; what he wanted was stability and low prices. If Lin Chen set the terms too rigidly, the man might simply replace him. But if he did not set them, the cost of later rework would drag him under. This was not a matter of pride. It was addition and subtraction in the ledger of survival.

Five minutes later, the phone lit up. Fine. We’ll do it your way. Send me the new script and the quotation sheet by nine Monday morning. Don’t screw this up.

Lin Chen packed up his computer and unplugged the network cable. When his left foot touched the ground, his knee gave slightly. He caught himself on the cabinet, paused for two seconds, then slowly made his way out. The motion-sensor lights in the corridor blinked on one by one with his footsteps, then went dark one by one behind him. He checked his bank balance: the final payment had arrived. After deducting the deposit and reserving the interest on the hospital loan, his available funds had climbed back to a little over two thousand. Not enough to cover Xiaoman’s next stage of targeted medication, but enough to buy out the next three days of breathing room.

By the time he stepped out of the complex, the night wind had already turned cold. He called a car and prepared to head back to the hospital. Then his phone screen lit up again. Not Old Zhao this time, but a WeChat message from the hospital caregiver: Mr. Lin, Xiaoman had a seizure just now. It lasted forty seconds. The doctor added a sedative, and she’s asleep now. If it’s convenient, please come early tomorrow morning. The attending physician wants to speak with the family about adjusting the medication plan. Also, the MRI films are out, and Radiology says a family member needs to sign to confirm.

Lin Chen stared at the line of text. Outside the car window, the streetlights joined into a dim yellow ribbon, stretching long halos across the glass. His fingers hovered over the screen, but he did not reply right away. By nine tomorrow morning he had to send the script and quotation sheet. At ten he had to face Director Li’s gamble agreement. In the afternoon he had to go to Radiology and collect the MRI results. Time was like a bow drawn to the limit, every string stretched to breaking point. He could not collapse, and he could not retreat.

He drew a deep breath and typed two words: Received.

The car drove into the night. Numbers flickered across the dashboard; the odometer reset to zero, then began counting again. He knew tomorrow would offer no buffer at all. Only marks on the scale, and the line he had no choice but to cross.